yesterday my ThinkPad silently rebooted as I unplugged my (external) USB disk, when it came backup USB was gone! The OS (Linux/Windows) still sees the USB host controller but non of the many devices I attached get recognized (dmesg shows nothing). Also some of the devices get power from the bus and others don't (I guess some of them only turn on the lights if the are ready). The internal Bluetooth is also gone (it's USB too) - so I guess the complete bus is gone or actually I think only a fuse got shot.
Anyway I spoke to the IBM support today and they told me it will be fixed within 7 days (wow!). To the question if this is a common problem I got told that it happens from time to time. WTF? USB is hotplug - it should be able to handle stuff like this.
Let's see how fast I get back my beloved black beauty :-]