I just experienced the weirdest problems ever with my Sony VAIO and the USB ports.
It started with me losing the USB mouse after plugging in an external 2.5″ harddrive in addition to an external cooling fan.
The mouse just died on me and wouldn’t start again so I disconnected all other devices, still no go.
I switched mouse, nope, didn’t work. Maybe it was a Linux / Ubuntu problem? When switching to command line (Alt + F6) it repeatedly said that various USB ports were disabled, couldn’t connect and so on. I tried modprobing various USB kernel modules but to no avail.
I rebooted into Vista, didn’t work either. Now I was really worried, what a weird hardware problem if it was really a hardware problem. I could still connect external harddrives, only the god damn mouse wouldn’t work.
Finally I found the answer in some obscure forum. Apparently somehow the firmware or something freaked out because of not being able to feed all the devices being connected, I suppose the external fan being the big culprit. This somehow locked the USB ports in a way that screwed up the mouse.
And the solution? Disconnect all power, the battery too in order to reset the machine for some 10 seconds, and voila up and running again.