PS/2 mouse jumpy in FC6 test1

[Pasha R]

After installing FC6 test1 and updating it to current development
packages, my PS/2 (microsoft) mouse became very jumpy. When I move a
mouse, after some moving forward, pointer suddenly jumps back. This
occurs in both XWindows and in console mode. I tried to plug same
mouse to USB port and it works ok this way. Never had such problems
before with previous Fedora releases.