I?m not sure how to reproduce this bug, as it happened at random during the course of the 48 hours of a gamejam I?ve particippated in.
Fortunatelly, I?ve not lost a lot of progress, but the crashes ocurred at least 5 times and as I was running against the clock, I couldn?t verify what could be causing the problems.
The OS was WIndows 7/64 bits, did someone experience crashes when saving?