My Blue MS Optical mouse was causing me problems (the middle click upset menu and dock sensitivity ... but that's another story!), so I installed the MS Intellipoint driver v5.0. This enabled me to map the mouse buttons to all kinds of things, even different things for different apps (much like USB overdrive, but free). This was great, except that the mouse acceleration speed was inconsistent -- fast user switching and going back to the Login page would alter the mouse speed. The MS driver preference pane let you use the OS X mouse acceleration, but seemed to keep overriding the OS X setting when changing apps (usually back to a slow crawl). The solution to stop this interference is as follows:
- Set up the MS driver for the click options you require.
- Select the option to use the OS X mouse acceleration speed.
- Reboot (this may be optional).
- The OS X mouse speed works perfectly until I complete the login, then it slows to a crawl.
- Kill the "MicrosoftMouseHelper" process using Terminal or the Activity Monitor.
- Go back to the OS X pref pane for the mouse and re-select your desired speed.
- Also, remove "MicrosoftMouseHelper" from your Login items.
Result: you can use the click-functionallity of the MS driver, without their crummy inconsistent mouse acceleration. Hooray!