I've been having problems with being unable to click sub-menus in My Applications and clicking sub-menus after right clicking an item. I had My Computer open while trying to figure out what was going on and saw that my two USB thumb drives were blinking. It seemed every time one of them would blink, it would close or prevent me from clicking a sub-menu. After I ejected both drives, every thing was good. If I plug the drives back in, I'm also good. If the drives are plugged in during startup or restart, I have this problem. All windows update are current. So not sure what could be causing this. There aren't any errors in the event log related to this.