Seems like some people are not exactly sure what the CPL mouse fix does.
In XP and Vista, turning off the 'Enhance pointer precision' checkbox *should* turn off acceleration.
BUT some older games un-intentionally turn it back on again (AFAIK, due to an API difference between XP and previous Windows versions).
If you have one of these games, one 'fix' (CPL & Cheese) is to configure the acceleration that does occur so that it uses a 1:1 straightline, rather than a curve that ramps up as the mouse speed increases. (Another fix is to enable DirectInput if your game supports that.)
(If your game is not affected, then CPL/Cheese fixes have NO effect when the 'Enhance pointer precision' checkbox is turned off.)
Defining a straightline is what the CPL fix attempts to do, but doesn't quite manage an exactly straight line and it does not work the same at all screen refresh rates.
WHEN the 'Enhance pointer precision' checkbox is ON (or your game forces it on):
At refresh rates < 80 Hz, it moves the mouse pointer < 1 pixel for each mouse count sent, which causes bizzare wobbling and slowdown if moving the mouse slowly right and down.
At refresh rates > 80 Hz, it moves the mouse pointer > 1 pixel for each mouse count sent, which causes bizzare wobbling and speedup if moving the mouse slowly left and up.
At any refresh rate, moving the mouse slowly in small circles causes the pointer to move up and left slowly.
NONE of those strange behaviours happen with Cheese's mouse fix.
(Except the 70 Hz 70.reg, which needs a tweak.)