I guess my hint is to try installing the MS mouse drivers. Or get a different mouse and see if the problem persists. Jens Jens Selvig ...lost in Montana... lstnmt at bresnan.net On Apr 9, 2007, at 9:32 AM, SE wrote: > No mouse drivers were ever installed. It worked fine in 10.3.9. And > another person in the department was upgraded to 10.4.7 and his 2- > button MS mouse works fine. No drivers were installed on his G4 > either. The only variable is he has an AGP G5, upgraded with a 1.4 > GHz Sonnet processor. Her computer is a MDD G4. Both have a gig of > RAM.