A very strange thing has happened, and I want to share the experience in case anyone else runs into a similar problem. During show start up we ran a lamp on sequence for 2 Elation Design Spot Pro250s. The auto follow cue puts both at 50/50 with shutter(strobe control channel) open and dimmer at full. When the sequence completed one of the unit's shutter was not open, but the lamp was struck. Only a few seconds later the tilt function started to "slip" if you will. Diagnostic tests we performed: Direct data line from console with tested cable- didn't change anything, so the data wasn't the problem. Checked fixture patch in console- not the problem Ran motor resets in "reset all" and om individual functions while lamped off- all functions normal, not the problem. Ran motor resets in "reset all" and on individual functions while lamped on- tilt slippage and other problems My conclusion was that the lamp was causing some sort of error that wasn't registering, so we replaced the lamp and everything worked fine. Thought I would share this because nothing in the manual lead me to believe that the lamp could be the issue, an no error codes were present to help find the culprit. Good luck with your Elations.