Well, the most common copy protection on the GBA, is based upon most of the emulators save type detection code. Specifically, SRAM will be assumed to be present, if the game writes to an SRAM location. The actual game paks do write to this location, even though there is no sram present, It will then read the location back. If it compares equally, it then does the next location, and the next. If all of them compare equally, which will only happen if sram is present, or your otherwise equally really unlucky, then the game refuses to run. Often times, the games will use EEPROM as its save type. Basically, try changing the save type, (and delete any save files that were created when you first started the game.) This should bypass that protection altogether.