I've recently upgraded to 13.04 on my work computer. Things work ok for around 15-20 minutes, but then the mouse ceases to work.
I can move the pointer around, top corner functionality still produces the switcher and can click the task bar at the top.
I can't however do anything else: * can't click buttons on menus, or any GUI object in any program * mouse pointer doesn't change on hovering over links or to a cursor over text objects
Only solution I've found is to push the power button until the machine turns off and on.
This isn't ideal, and only one of the many problems I've found after foolishly updating my Ubuntu.
Why do they break things that work? Do they want people to move away from ubuntu? Such a strange business practice!