You need to make sure that that ROM has a proper ROM Header, GPSP Can't save the ROM if it isn't listed in it's configuration files, and the rom you're playing's ROM header is what GPSP checks to see how to save the data.
About that crash, try changing some settings in your GPSP, and try with a clean rom, from a diferent source than the one you got your original one.
ALSO, if that ROM Hack is a hack of Ruby or Sapphire, make sure you're not using a v1.1 version of the rom, but instead a v1.0, you can check this in the bottom lefthand corner of A-Map when you open the ROM.
Anyways, check youtube for better tuts on how to add a ROM to your GPSP list, and check the Sienna Thread for info on that bug, if you can't find any info, tell people in that thread.
About that crash, try changing some settings in your GPSP, and try with a clean rom, from a diferent source than the one you got your original one.
ALSO, if that ROM Hack is a hack of Ruby or Sapphire, make sure you're not using a v1.1 version of the rom, but instead a v1.0, you can check this in the bottom lefthand corner of A-Map when you open the ROM.
Anyways, check youtube for better tuts on how to add a ROM to your GPSP list, and check the Sienna Thread for info on that bug, if you can't find any info, tell people in that thread.