I’m not sure how long Ubuntu has been doing this, but the other day while trying out Half-Life 2 in Wine, I was noticing that I couldn’t move with the keyboard and look around with the mouse at the same time – I was thinking it was just a HL2 / Wine specific problem, until I noticed the same thing happening in my browser, I couldn’t move the mouse while typing or holding any key on the keyboard.
I found a fix on a older blog post for getting a Macbook to play along with Feisty – fortunately the fix still seems valid in Karmic. In /etc/defaults/mouseemu:
Uncomment “TYPING_BLOCK…”, change 300 to 0, save
sudo /etc/init.d/mouseemu restart