Sometimes when I'm doing something in my computer (Ubuntu 13.04) the mouse and the keyboard just stop working. The mouse still moves, but if I try to click in the menu or even try to restart the computer through the menu, it doesn't appear. I have to turn it off by the button and stop all my work.
It always happened to me, even when I was using the 12.04 or 12.10. I have already losted some designs I was doing and a lot of other works. What can I do?
I got some screenshots when this happened (I don't know how. The PrintScreen key shouldn't be working):
And it always happen when my computer goes crazy and starts to turn the volume down (that thing happens in Windows too, but the error with mouse and keyboard just in Ubuntu)...
It happened twice while I was writing this!
PS: Sorry about anything written wrong, I'm still learning English!