Mouse sensitivity spontaneously changes

Question

I'm using a Microsoft IntelliMouse Optical on Windows 7 x64 with whatever basic default drivers it loads, and lately I've had an annoying issue where the sensitivity would change out of the blue, being cut to maybe 25% of what it's normally at. I thought it was related to a particular game (Civ 5 and/or SC2); but it happens outside of the game and some searches have turned up nothing mentioning them being related.

When the sensitivity drops, adjusting the sensitivity in the control panel down then back up does nothing, the only thing that appears to fix the issue is unplugging/replugging the mouse, coming out of suspend or restarting.

Aside from some basic programs that run all the time (e.g. Google Talk, etc), I can't figure out any obvious connection.

As it's probably impossible to come up with any sort of fix without first knowing what's the cause, how can I go about looking for the possible source of this issue?

Answer 1

First place I'd look at is what you're using for a mousepad. Too much of a solid color or too shiny of a surface won't be read too well by most mice. Texture and color help with keeping the reading of a mouse's movements smooth and even.

Answer 2

Try to install the latest version IntelliPoint 8.0 64-bit for Windows 7 from Microsoft :

Download Mouse and Keyboard Software

Answer 3

This seemed to end up being a hardware issue, as a few days ago I became confused by the Windows "Disconnected Hardware/New Hardware" noise playing at bizarre times, then noticing that my mouse locked up. If I moved it really quickly, or even shook it somewhat hard, it would disconnect/reconnect in rapid succession.

The sensitivity could be some other issue as well, as it disconnecting/reconnecting should be a works-fine-or-not-at-all thing. Have not had the issue with a new mouse, so oh well.