I find this to be a very buggy version. The previous release was more stable in many ways. In Photoshop, there is a slight delay with button releases and then responses using a marble mouse. It also reset a number of system preferences and window views after restart. I repaired all permissions after uninstalling the previous version and removing the remaining files. This is exactly what the beta version of this driver did. I am considering switching back to the previous release after I take a peek at this MouseZoom thing. Thanks for the tip. Does it use a lot of CPU like USB Overdrive I wonder? Has anyone noticed unusual spikes every so often in CPU monitor? I have. They weren't there before I installed either version.