As long as it is according to idpf standards it shouldn't be impossible to create a good checker. But that's another topic.
Im not the only one getting this problem:
http://idpf.org/forum/topic-518
Would be great if some smart person out there could explain what is going on. Strangely enough this guy is getting the exact same problem, on the EXACT SAME LINES: (7,52) and (1,1). Messed up. Is this a bug?