I have Win7 64 bits, and I
always use hibernation. And usually turn LFS to windowed mode before exiting it.
Yesterday, I woke up my computer, started LFS, and went into a server.
After a few seconds I pressed Shift+F4, and the bug started.
LFS tries to set to full screen, but after a tenth of a second it minimizes itself. Every try to maximize results into an autominimizing.
If I was able to press Shift+F4 just in the moment it is maximizing it turns to windowed mode again.
The bug repeated again trying to set to full screen. After a clean restar of LFS and after killing LFS process.
I had to reboot my computer (not hibernate), and now everything is fine again