it's so weired that i have to plug/unplug in my usb devices every time booting ubuntu. it happens for both installing ubuntu and booting ubuntu (10.10 and 11.10)
the scenario is like:
1.bios checking -> 2.grub start -> 3.keyboard & mouse led OFF (black screen with a cursor on top-left) -> 4.i plug/unplug in any usb devices -> 5.everything is back to normal and ubuntu started
it's really frustrating :( please advise the solution.