Okay, I narrowed it down to another vbulletin addon, wowhead itemstats. I've disabled that for now, and the gallery becomes accessible. However a non-logged in user of mine was browsing in IE and came up with this error. As I really need to go to bed now, I'll post it up and then search the photoplog forums in the morning -_- This is internet explorer version 6
Code:
Content visible to registered users only.