What's wrong with my save files?

[Dukelord]

I just can't figure it out,like my save files are crashing or something...I use F5 for quick save and F7 for quick load,after a while,when I wanna load a game using F7,it just doesn't come up and the whole emulator hangs.

[Allnatural]

The states could be corrupted. It's recommended that you primarily use native saves.

[Dukelord]

I guess that's what I'm gonna be doing from now on.
Thanks.