So this seems to be a problem that only happens when running UT @ really high resolutions (above 1920x1080) on my new monitor.
If I set UT to 2560x1440 in the ini (to match my new monitor res) and load UT, I have massive negative accel and my mouse feels like it's in molasses. If I set it in-game to something like 1920x1080 and then back to 2560x1440, the problem disappears and my mouse is normal again until I restart UT, which causes the problem to reappear. I have to load UT and switch my res back-and-forth in-game to get rid of negative accel.
Anyone else experience this or have any suggestions to fix it?
I also get a crash and the "Runaway loop detected (over 1000000 iterations)" error if I hit the esc key too soon after loading UT.