Jerky Mouse Movement in Xorg

I'm using a recent version of Debian's GNU/HURD DVD and upgraded to 
current. My main problem lies with the very jerky movement of the mouse 
cursor. If I move the mouse UNNATURALLY slow, the cursor doesn't jerk. 
Outside of X and within the HURD's console, the movement of the cursor 
is extremely smooth so the problem lies with using this PS/2 mouse in X. 
I've tried adjusting some of the acceleration factors within X 
("AccelerationProfile" in xorg.conf) with some reduction in the 
jerkiness, but not nearly enough. Apparently, X can't read the mouse's 
movement accurately if the mouse is moved too rapidly. I'd certainly 
appreciate any input from readers in order to solve or heavily mitigate 
the jerkiness. BTW, I'm favorably impressed with the current state of 
Debian's version of GNU's HURD. I'm looking forward to a formal release 
of the HURD by Debian this year if possible. TIA