When I tried to take flats with CCDAutopilot at GSSP, it suddenly only took small subframes!!!
I restarted CCDAP, TSX, rebooted the computer, plugged the camera out and in ... nothing. It kept switching subframes on when it took flats. I ended up borrowing John's flat panel and used that for flats.
At home, I investigated more but couldn't figure out what was wrong. There was nothing suspicious in the log file. I also couldn't find any setting in CCDAP. I posted about this on the CCDWare forum. And John Smith (as usual) asked for a log file. That evening, I tried it again to get a log file, but was then distracted and kept CCDAP running.
... and suddenly realized that the flats that CCDAP took were full frame!!!
After more investigation, it turns out that CCDAP started to take the test frames (to check if the right brightness level is reached) as subframes and then takes that real flats as full frames. Probably to make the initial test frames faster to download. I'm sure that was in some release notes ...