Which SNES emulator are you running? The reason I ask is because there are two that I know of, and each requires you to place roms in different folder locations of your SMC card.
SNES wants you to put them on the \GPMM\SNES folder.
SNES9XGP wants you to put them in the \GPMM\ folder.
I was running into the same problem of the unit crashing/reseting when I was running SNES9XGP with all of my roms in the \GPMM\SNES folder until I read the README file. I moved some of them to the \GPMM\ folder, now everything is fine.