I'm using a developing environment called devkitPro and the actually coding is done in C. I've been piling information together from various tutorials on gbadev.org and around the Internet until today when I discovered that this guy wrote a book on GBA Programming and he posted all of the chapters, tools, and programs in the book on his website. The guy who wrote it obviously knows what he's talking about which is nice because I didn't get that feeling with a lot of the tutorials I read by amateur developers (which, frankly, is what I am at this point).
gotta go eat dinner. I can't say why the ROM didn't work for you but try 1) deleting the save file that it created 2) switching from 64k to 128k or vice versa or 3) downloading the file again. k gotta go