Ok thanks guys. Having now sorted that problem, another has arisen. It seems that intermittently that CCDAP cannot open the guider and it now aborts very frequently. That unfortunately leaves the dome open and in an unprotected state. Do I need to update the firmware on the camera. One of the drivers appears to need updating (STX???), it appears second on the list. Is this a communication problem between CCDAP and the camera or CCDAP and Maxim?