Strange mouse problems
The comp I'm running UT3 on is an HP Pavilion a747c with a 2.8GHz P4, 2 gigs of ram and a Geforce 6600GT 256MB PCI-E card, running Windows XP SP2.
This problem didn't start occurring until after I had patched to 1.1. When I get in the menu the mouse seems to work as it should. It isn't until the match actually starts that moving the mouse doesn't do anything for me. I'll even back up to the menu and it will work there, and even the buttons to fire will work in-game, but actually moving the mouse isn't moving my view at all. Has anyone else experienced this and/or know of a possible solution?
You should try renaming your UTEngine.ini and then trying to run the game. A new file will be created for you and may resolve your issue, although any user settings you had would be lost.