I am seeing this in Jaunty as well.   Even now with the latest updates.
It seems to happen when I raom from one AP to the next.

It renders the card useless in that I need to do a hard shutdown (Power down) in order to reset the card.

It then works again.

uname -a
Linux tux 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux

Apr 20 17:41:22 tux kernel: [ 1134.413027] wlan0: authenticate with AP 00:80:48:7e:07:00
Apr 20 17:41:22 tux kernel: [ 1134.414443] wlan0: authenticated
Apr 20 17:41:22 tux kernel: [ 1134.414449] wlan0: associate with AP 00:80:48:7e:07:00
Apr 20 17:41:22 tux kernel: [ 1134.416559] wlan0: RX ReassocResp from 00:80:48:7e:07:bc (capab=0x421 status=0 aid=1)
Apr 20 17:41:22 tux kernel: [ 1134.416568] wlan0: associated
Apr 20 17:41:24 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:41:43 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:41:49 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:42:19 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:42:31 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:43:19 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:... to 00:80:48:7E:07........
Apr 20 17:43:31 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:44:43 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:44:49 tux NetworkManager: <debug> [1240242084.776621] periodic_update(): Roamed from BSSID 00:80:48:7E:1F:.... to 00:80:48:7E:07........
Apr 20 17:46:19 tux NetworkManager: <debug> [1240242379.003371] periodic_update(): Roamed from BSSID 00:80:48:7E:07:... to (none) ((none)) Apr 20 17:54:37 ibmtux kernel: [ 1928.960552] wlan0: authenticate with AP 00:80:48:7e:1f:d0
Apr 20 17:54:37 tux kernel: [ 1929.160354] wlan0: authenticate with AP 00:80:48:7e:1f:d0
Apr 20 17:54:37 tux kernel: [ 1929.194714] wlan0: authenticated
Apr 20 17:54:37 tux kernel: [ 1929.194725] wlan0: associate with AP 00:80:48:7e:1f:d0
Apr 20 17:54:37 tux kernel: [ 1929.392145] wlan0: associate with AP 00:80:48:7e:1f:d0
Apr 20 17:54:37 tux kernel: [ 1929.456824] wlan0: RX ReassocResp from 00:80:48:7e:1f:d0 (capab=0x421 status=0 aid=1)
Apr 20 17:54:37 tux kernel: [ 1929.456831] wlan0: associated
Apr 20 17:56:28 tux kernel: [ 2039.697940] wlan0: authenticate with AP 00:80:48:7e:1f:d0
Apr 20 17:56:28 tux kernel: [ 2039.744970] wlan0: Failed to config new BSSID to the low-level driver
Apr 20 17:56:28 tux kernel: [ 2039.773468] phy0: failed to set freq to 2412 MHz for scan
Apr 20 17:56:28 tux kernel: [ 2039.810841] phy0: failed to set freq to 2417 MHz for scan
Apr 20 17:56:28 tux kernel: [ 2039.848226] phy0: failed to set freq to 2422 MHz for scan
....
pr 20 17:56:29 ibmtux kernel: [ 2040.970453] phy0: failed to set freq to 5770 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.007814] phy0: failed to set freq to 5775 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.045178] phy0: failed to set freq to 5780 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.082543] phy0: failed to set freq to 5785 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.119917] phy0: failed to set freq to 5790 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.157274] phy0: failed to set freq to 5795 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.194639] phy0: failed to set freq to 5800 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.232357] phy0: failed to set freq to 5805 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.269721] phy0: failed to set freq to 5810 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.307089] phy0: failed to set freq to 5815 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.344493] phy0: failed to set freq to 5820 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.381856] phy0: failed to set freq to 5825 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.419254] phy0: failed to restore operational channel after scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.481665] phy0: failed to set freq to 2412 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.519198] phy0: failed to set freq to 2417 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.556740] phy0: failed to set freq to 2422 MHz for scan
Apr 20 17:56:29 ibmtux kernel: [ 2041.594690] phy0: failed to set freq to 2427 MHz for scan