I have been having a lot of problems with Solidworks since I installed a Microsoft Optical Trackball. I am presently using SW2007 sp3.1. I downloaded the latest driver for my video card Quadro FX 1400, and used the latest Microsoft Mouse driver for the trackball. My VAR does not understand what the problem is. It happens when I work on parts, assemblies, and drawings. My screen goes either black or white if I am modeling parts or the drawing just blows up if I am working on a drawing. Has anyone else seen this problem. I really like the MS Trackball, but this is getting ridiculous. I have used this same Trackball previously on different computers and never saw crashes like this. Rich