Half of my homebrew doesn't start.

I'm on firmware 3.71 M33, and I've checked recovery mode and the homebrew folder is set to 1.50 kernel. My SNES and genesis emulator doesn't work, but the NES one does. Half of the rom's doesnt work though.
I've tried formating the memory stick and replacing all the homebrew programs.
The ISO's work fine though.
Thanks.

Yes, I did now, the 1.50 ad-on wasn't installed, so thanks. It all works fine now. : )