Comment 52 for bug 126369

I have the same (type of) error on a T61 with kernel 2.6.22-14-generic.
The single USB Port on the right works all the time. The two USB-Ports on the left sometimes don't work. I couldn't figure out any regularity, when the ports get disabled.
However, when I reload the kernel module for USB with 'sudo modprobe -r --force ehci-hcd' the USB ports work again, also for a longer period than 10 min. (thx to Nemanja Stefanovic tip!)