If it makes you feel any better Karl, I've just spent nearly 2 hours aligning and then finding NGC300, changed the battery in my camera and let it do it's thing. 1 hour in and i went to check my tracking. It had started to go off. A small adjustment and I switched back to camera control and my scope's power supply died
First clear night with no moon for a while and as always happens..... something else went wrong.
Time to make myself a more reliable power supply.