Exactly same problem & results for me, with Belkin's F5D7050B device. Usb id is 050d:705a. It worked fine with the legacy rt73 driver from previous kernels. But not with rt73usb that came with the latest kernel update (2.6.20-11-generic).
lsmod reports the following drivers: rt2500usb 30592 0 rt73usb 33536 0 rt2x00lib 11904 2 rt2500usb,rt73usb usbcore 134280 5 rt2500usb,rt73usb,ehci_hcd,uhci_hcd iwconfig reports: lo no wireless extensions. eth0 no wireless extensions. wmaster0 IEEE 802.11g Frequency:2.412 GHz RTS thr:off Fragment thr=2346 B wlan0 IEEE 802.11g ESSID:"" Mode:Managed Frequency:2.412 GHz Access Point: Not-Associated RTS thr:off Fragment thr=2346 B Encryption key:off Link Quality:0 Signal level:0 Noise level:0 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 -- rt73usb seems to fail https://launchpad.net/bugs/86980 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs