When I'm playing on SSF Emulator on full screen mode, if I switch between open windows (e.g. alt+tab), SSF crashes and I lose all the game progress.

This just happens on full screen mode, but it's a problem, because I'm focused on the game, if I forget and leave SSF window, the application crashes and I lose all my progress.

This happens in every game that I have played up to now.

Any solution?

Additional information:
SSF 0.12 beta R4
Windows 8.1
DirectX 11.0

Thanks in advance!