I'm working on a site which is a kind of hash up of the old site, integrating a new layout. There's so much going on in the header it's hard to work out what's what but I have noticed it's calling 3 different versions of the jQuery library. Assuming this was because of updates to the site and previous developers being careless, I removed all but the most up to date link & refreshed the page. This broke it!! After much tinkering I discovered that unless I have all instances included, something stops working. What's more, if the links are in any other order, they don't work!? WTF is going in!!?!!