Mouse acceleration in Windows XP

I've got an Intellimouse Explorer and just installed the XP Intellimouse software (on XP Pro install). I can not locate the "acceleration" feature that is supposed to be located on the "Pointer Options" tab of the mouse control panel. Where did it go?

 

running 2k, don't have it either, pointer speed is there, but no acceralation

 

I just re-installed the Version 3.2 that came with my mouse and I do have the option back. Interestingly enough, I did get a couple of messages stating that this version was incompatible with my Windows version, yet it seems to be working just fine. The main difference I can see is with the 4.0 build, you lose the acceleration feature (which I Like) and you gain the "enhance pointer precision."

 

doh, little mouse trouble tonight myself, did some driver replacing, the new drivers have the acceleration located under the advanced button on the pointer speed section of pointer options

 

That is where they are located on the 3.2 build. On the 4.0 release, there is no advanced option button that I can find.