I have upgraded from Ubuntu 10.04 to 11.04 and I encountered a strange problem with my keyboard.
While I am typing sometimes the last character I typed sticks, so it acts like I keep holding the the key down without releasing it.
For example if I typed "Ubuntu" the last "u" could stick and would be producing "Ubuntuuuuuuuuuuuuuuuuu" until I pressed any key on the keyboard. This happens randomly and I can't figure out under which circumstances this happens. I have never experienced it on Ubuntu 10.04, so I doubt that this is something wrong with my hardware.