We wanted to try running linux on a macbook air rev B using an open suse 11.1 RC1 live CD and the macbook air external drive. The system appeared to hang partway through the startup so we rebooted in Mac OS where something odd happened. Now the USB port no longer worked. It had power (the optical mouse lit up) but no device would work, nor would any kind of external drive mount. Other USB internal devices functioned normally (iSight, keyboard, trackpad, bluetooth) but the port was non-functional. We tried several diagnostics/repairs (fsck, PRAM flashing, repairing disk permissions, hardware check) but nothing worked, nor did installing the EFI firmware update (released earlier this week). Eventually we installed several other available updates, including the SMC Firmware update released this week, and suddenly the USB port was functioning normally again. Not sure exactly what went wrong or exactly what fixed the problem, but glad it's working again. Just wanted to pass on this info in case anyone else runs into similar problems or before anyone tries the same thing.