I am a new member so i dont know if this has been discused before,so if it has i am sorry. I think i saw something that was a little weird to me. When peter was on the roof before they toasted mr. stay puft it looks like his pack is broken or incomplete. You see like the right side is missing and you can see all of the wiring. Just post a comment and let me know what you guys think or is it my eyes playing tricks on me,because i watched the movie tomany times lol.
You’re probably just seeing the Ribbon Cable.
if you don’t see any type of wiring, then the pack is not complete.
I don’t see exactly what you are seeing, but when they’re up on the roof talking to each other there they are using stunt packs in many of the shots. they’re noticibly different (to people who read these boards i suppose), that may be what you’re seeing. anyway, the more visible wires the better 
Are you on about the part where they discuss crossing the streams? I think that was a stunt pack Peter was wearing which explains it’s state.
They used a lot of the foam stunt packs in the “rooftop” scene, and they didn’t really bother to put alot of the wires on. It pretty noticable when they ware 'em though, because the packs aren’t compleletly black and sometimes you can see the ion arm being bent when they’re against the wall. lol