I'm still seeing this problem in Karmic:

Linux bauer 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:04:26 UTC 2009 i686 GNU/Linux

[14860.672099] hub 4-0:1.0: unable to enumerate USB device on port 1
[14880.196291] usb 1-3: new high speed USB device using ehci_hcd and address 3
[14880.331612] usb 1-3: configuration #1 chosen from 1 choice
[14880.378332] Initializing USB Mass Storage driver...
[14880.379177] scsi6 : SCSI emulation for USB Mass Storage devices
[14880.379300] usb-storage: device found at 3
[14880.379303] usb-storage: waiting for device to settle before scanning
[14880.379316] usbcore: registered new interface driver usb-storage
[14880.379320] USB Mass Storage support registered.
[14885.376735] usb-storage: device scan complete
[14885.377219] scsi 6:0:0:0: Direct-Access     MicroNet Volume Set # 00  0100 PQ: 0 ANSI: 4
[14885.377753] sd 6:0:0:0: Attached scsi generic sg3 type 0
[14885.383209] sd 6:0:0:0: [sdc] 3906248704 512-byte logical blocks: (1.99 TB/1.81 TiB)
[14885.385147] sd 6:0:0:0: [sdc] Write Protect is off
[14885.385151] sd 6:0:0:0: [sdc] Mode Sense: 11 00 00 00
[14885.385154] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[14885.386264] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[14885.386268]  sdc: sdc1
[14885.403639] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[14885.403644] sd 6:0:0:0: [sdc] Attached SCSI disk
[14888.620032] usb 1-3: reset high speed USB device using ehci_hcd and address 3
[14903.732041] usb 1-3: device descriptor read/64, error -110
[14918.948030] usb 1-3: device descriptor read/64, error -110
[14919.164040] usb 1-3: reset high speed USB device using ehci_hcd and address 3
[14934.276037] usb 1-3: device descriptor read/64, error -110
[14949.492061] usb 1-3: device descriptor read/64, error -110
[14949.708059] usb 1-3: reset high speed USB device using ehci_hcd and address 3
[14954.729058] usb 1-3: device descriptor read/8, error -110
[14959.848367] usb 1-3: device descriptor read/8, error -110
[14960.064037] usb 1-3: reset high speed USB device using ehci_hcd and address 3
[14965.084165] usb 1-3: device descriptor read/8, error -110
[14970.204099] usb 1-3: device descriptor read/8, error -110
[14970.308065] usb 1-3: USB disconnect, address 3
[14970.308828] scsi 6:0:0:0: Device offlined - not ready after error recovery
[14970.420039] usb 1-3: new high speed USB device using ehci_hcd and address 4
[14985.532041] usb 1-3: device descriptor read/64, error -110
[15000.748815] usb 1-3: device descriptor read/64, error -110
[15000.964037] usb 1-3: new high speed USB device using ehci_hcd and address 5
[15016.076036] usb 1-3: device descriptor read/64, error -110
[15031.292059] usb 1-3: device descriptor read/64, error -110
[15031.508043] usb 1-3: new high speed USB device using ehci_hcd and address 6
[15036.528103] usb 1-3: device descriptor read/8, error -110
[15041.648491] usb 1-3: device descriptor read/8, error -110
[15041.864057] usb 1-3: new high speed USB device using ehci_hcd and address 7
[15046.884090] usb 1-3: device descriptor read/8, error -110
[15052.004394] usb 1-3: device descriptor read/8, error -110
[15052.108045] hub 1-0:1.0: unable to enumerate USB device on port 3
[15052.376038] usb 4-1: new full speed USB device using uhci_hcd and address 3
[15067.488035] usb 4-1: device descriptor read/64, error -110
[15082.704040] usb 4-1: device descriptor read/64, error -110
[15082.920075] usb 4-1: new full speed USB device using uhci_hcd and address 4
[15098.032057] usb 4-1: device descriptor read/64, error -110
[15113.248036] usb 4-1: device descriptor read/64, error -110
[15113.464032] usb 4-1: new full speed USB device using uhci_hcd and address 5
[15118.485331] usb 4-1: device descriptor read/8, error -110
[15123.605888] usb 4-1: device descriptor read/8, error -110
[15123.820038] usb 4-1: new full speed USB device using uhci_hcd and address 6
[15128.841433] usb 4-1: device descriptor read/8, error -110
[15133.961988] usb 4-1: device descriptor read/8, error -110
[15134.064046] hub 4-0:1.0: unable to enumerate USB device on port 1