Now that you got it the conventional way, I'll tell you about a switch for your Pointer section of your XF86Config-4 file that works well for that purpose. Its:
Option "Resolution" "400"
This line, when added to your mouse section changes the pixel resolution that your mouse works at. I had a Labtec Optical mouse that was jumpy when used. I added that value (400 worked well for me. BTW Microsoft defaults theirs to 300 and mice work on Windows). I noticed that the higher the resolution, the farther my mouse moved for a given movement. It didn't go wierd as messing with the accelleration can sometimes do. This took me many hours of googling to find so I thought I'd share it. This a more "direct" way of messing with your mouse, so I didn't mention it before. But, someone might find this useful