That's a new one. I've seen people have trouble with the space bar and hand tool.
Have you played any full-screen Flash videos lately? If so, you might try some of the fixes for the hand tool: http://forums.adobe.com/message/2325795
no...no full screen flash etc....reistalled FW from disc (takes soooo long)....still had same problem....deleted the config file in application data folder and all is now as it should be.