Having problems loading my save game file from my memory card via someone else xbox360?

As my long title says having problems loading my game data from my memory card while playing on my friends xbox 360. so yeah any one know why I cannot load my saved data via his xbox360? Plus my save date is on the memory unit because my xbox360 does not have a hard drive but idk. But yeah my friend was logged onto his gamer tag or what ever it called. so could that b it? sry inf this does not make much since I'm just really confused..