Printer is visible and prints when used from a client that has Xubuntu 7.04 in it.

I tried the Printing troubleshooter from the problematic Xubuntu 8.04 computer and got this:
Page 1 (Choose printer):
{'cups_dests_available': [('PDF', None)], 'cups_queue_listed': False}
Page 2 (Printer not listed):
{'cups_connection_failure': False}
Page 3 (Local or remote?):
{'printer_is_remote': True}
Page 4 (Remote address):
{'remote_server_ip_address': '192.168.0.102',
 'remote_server_name': 'jarnos-desktop'}
Page 5 (Check network printer sanity):
{'remote_server_connect_ipp': True,
 'remote_server_cups': True,
 'remote_server_name_resolves': ['192.168.0.102',
                                 '192.168.0.102',
                                 '192.168.0.102'],
 'remote_server_try_connect': 'jarnos-desktop'}
Page 6 (Choose network printer):
{'remote_cups_dest': <cups.Dest object at 0x86ea600>,
 'remote_cups_instance': None,
 'remote_cups_queue': 'HP_LaserJet_5L',
 'remote_cups_queue_listed': True}
Page 7 (Queue not shared?):
{'remote_cups_queue_attributes': {'auth-info-required': u'none',
                                  'charset-configured': u'utf-8',
                                  'charset-supported': [u'us-ascii',
                                                        u'utf-8'],
                                  'color-supported': False,
                                  'compression-supported': [u'none', u'gzip'],
                                  'copies-default': 1,
                                  'copies-supported': (1, 100),
                                  'cups-version': u'1.3.7',
                                  'device-uri': u'hp:/par/HP_LaserJet_5L?device=/dev/parport0',
                                  'document-format-supported': [u'application/octet-stream',
                                                                u'application/pdf',
                                                                u'application/postscript',
                                                                u'application/vnd.cups-postscript',
                                                                u'application/vnd.cups-raw',
                                                                u'application/vnd.hp-hpgl',
                                                                u'application/x-cshell',
                                                                u'application/x-csource',
                                                                u'application/x-perl',
                                                                u'application/x-shell',
                                                                u'image/gif',
                                                                u'image/jpeg',
                                                                u'image/png',
                                                                u'image/tiff',
                                                                u'image/x-bitmap',
                                                                u'image/x-photocd',
                                                                u'image/x-portable-anymap',
                                                                u'image/x-portable-bitmap',
                                                                u'image/x-portable-graymap',
                                                                u'image/x-portable-pixmap',
                                                                u'image/x-sgi-rgb',
                                                                u'image/x-sun-raster',
                                                                u'image/x-xbitmap',
                                                                u'image/x-xpixmap',
                                                                u'text/html',
                                                                u'text/plain',
                                                                u''],
                                  'finishings-default': 3,
                                  'finishings-supported': 3,
                                  'generated-natural-language-supported': [u'en-us'],
                                  'ipp-versions-supported': [u'1.0', u'1.1'],
                                  'job-hold-until-default': u'no-hold',
                                  'job-hold-until-supported': [u'no-hold',
                                                               u'indefinite',
                                                               u'day-time',
                                                               u'evening',
                                                               u'night',
                                                               u'second-shift',
                                                               u'third-shift',
                                                               u'weekend'],
                                  'job-k-limit': 0,
                                  'job-page-limit': 0,
                                  'job-priority-default': 50,
                                  'job-priority-supported': 100,
                                  'job-quota-period': 0,
                                  'job-sheets-default': (u'none', u'none'),
                                  'job-sheets-supported': [u'none',
                                                           u'classified',
                                                           u'confidential',
                                                           u'secret',
                                                           u'standard',
                                                           u'topsecret',
                                                           u'unclassified'],
                                  'marker-change-time': 0,
                                  'media-default': u'A4',
                                  'media-supported': [u'Default',
                                                      u'Tray1',
                                                      u'Tray2',
                                                      u'Tray3',
                                                      u'Tray4',
                                                      u'Envelope',
                                                      u'Manual',
                                                      u'Letter',
                                                      u'A4',
                                                      u'11x17',
                                                      u'A3',
                                                      u'A5',
                                                      u'B5',
                                                      u'Env10',
                                                      u'EnvC5',
                                                      u'EnvDL',
                                                      u'EnvISOB5',
                                                      u'EnvMonarch',
                                                      u'Executive',
                                                      u'Legal'],
                                  'multiple-document-handling-supported': [u'separate-documents-uncollated-copies',
                                                                           u'separate-documents-collated-copies'],
                                  'multiple-document-jobs-supported': True,
                                  'multiple-operation-time-out': 60,
                                  'natural-language-configured': u'en-us',
                                  'notify-attributes-supported': [u'printer-state-change-time',
                                                                  u'notify-lease-expiration-time',
                                                                  u'notify-subscriber-user-name'],
                                  'notify-events-default': [u'job-completed'],
                                  'notify-events-supported': [u'job-completed',
                                                              u'job-config-changed',
                                                              u'job-created',
                                                              u'job-progress',
                                                              u'job-state-changed',
                                                              u'job-stopped',
                                                              u'printer-added',
                                                              u'printer-changed',
                                                              u'printer-config-changed',
                                                              u'printer-deleted',
                                                              u'printer-finishings-changed',
                                                              u'printer-media-changed',
                                                              u'printer-modified',
                                                              u'printer-restarted',
                                                              u'printer-shutdown',
                                                              u'printer-state-changed',
                                                              u'printer-stopped',
                                                              u'server-audit',
                                                              u'server-restarted',
                                                              u'server-started',
                                                              u'server-stopped'],
                                  'notify-lease-duration-default': 86400,
                                  'notify-lease-duration-supported': (0,
                                                                      2147483647),
                                  'notify-max-events-supported': 100,
                                  'notify-pull-method-supported': [u'ippget'],
                                  'notify-schemes-supported': [u'mailto',
                                                               u'rss',
                                                               u'testnotify'],
                                  'number-up-default': 1,
                                  'number-up-supported': [1, 2, 4, 6, 9, 16],
                                  'operations-supported': [2,
                                                           4,
                                                           5,
                                                           6,
                                                           8,
                                                           9,
                                                           10,
                                                           11,
                                                           12,
                                                           13,
                                                           16,
                                                           17,
                                                           18,
                                                           20,
                                                           22,
                                                           23,
                                                           24,
                                                           25,
                                                           26,
                                                           27,
                                                           28,
                                                           34,
                                                           35,
                                                           16385,
                                                           16386,
                                                           16387,
                                                           16388,
                                                           16389,
                                                           16390,
                                                           16391,
                                                           16392,
                                                           16393,
                                                           16394,
                                                           16395,
                                                           16396,
                                                           16397,
                                                           16398],
                                  'orientation-requested-default': None,
                                  'orientation-requested-supported': [3,
                                                                      4,
                                                                      5,
                                                                      6],
                                  'page-ranges-supported': True,
                                  'pages-per-minute': 1,
                                  'pdl-override-supported': [u'not-attempted'],
                                  'port-monitor': u'none',
                                  'port-monitor-supported': [u'none'],
                                  'printer-current-time': '(IPP_TAG_DATE)',
                                  'printer-error-policy': u'retry-job',
                                  'printer-error-policy-supported': [u'abort-job',
                                                                     u'retry-job',
                                                                     u'stop-printer'],
                                  'printer-info': u'HP_LaserJet_5L',
                                  'printer-is-accepting-jobs': True,
                                  'printer-is-shared': True,
                                  'printer-location': u'jarnos-desktop',
                                  'printer-make-and-model': u'HP LaserJet 5L Foomatic/ljet4 (recommended)',
                                  'printer-more-info': u'ipp://jarnos-desktop:631/printers/HP_LaserJet_5L',
                                  'printer-name': u'HP_LaserJet_5L',
                                  'printer-op-policy': u'default',
                                  'printer-op-policy-supported': [u'default'],
                                  'printer-state': 3,
                                  'printer-state-change-time': 1214405593,
                                  'printer-state-message': u'',
                                  'printer-state-reasons': u'none',
                                  'printer-type': 143364,
                                  'printer-up-time': 1214405967,
                                  'printer-uri-supported': [u'ipp://192.168.0.102:631/printers/HP_LaserJet_5L'],
                                  'queued-job-count': 0,
                                  'uri-authentication-supported': [u'requesting-user-name'],
                                  'uri-security-supported': [u'none']}}