Yeah well you can't use IMAGES as a URL folder name anywhere on the forums:
/images/
I just did there, and if I'm right it'll have renamed it to "images2". Try it yourself if you want :S Anyways this might cause problems with people that host their sigs and stuff on their own sites as most people use that kind of url. Dunno if you can fix it :S
its just a skin problem, once we have the v5 skin on here that problem will no longer exist... but theres not a whole lot I can do until then, its not a vbulletin problem its a folder conflict problem.