Ok....

Got a lot of code, and been trying to add some more, but then it wont assemble and run, if I take out some code, then its ok. Now I know what you're thinking... that the new code was at fault, but that is not the case, it happens no matter what code I try to insert.
I can // out some code that is included on assembly that is not needed at the moment( but will be) and I can carry on as normal. Trouble is, that when I try to re-include that code, it wont assemble again.
Hope this makes sense, I mean its not huge huge by any means, whole thing publishes at under 400MB.
I just cant seem to grasp what I am supposed to do? I mean, its a game programming program, and thai limitation seems silly to me?
Thanks for looking too...
F.