There are several threads about this issue lately and that the BEFORE ENGINE START checklist does not start anymore after updating to 1.0.0.4. This a coincidence because GSX updated its pushback function nearly at the same time. As we did not change anything at that time the reason for this issue is the GSX update only. We are investigating it currently but it is hard to reproduce the issue. Also the FSDT developers as well as our developer, who created the GSX immersion, are still on vacation.