with an & in url BBCode, clicking the link text will change any '&' into '&amp;', which breaks some links. in the editor it appears fine, but somewhere between there and the external link page it breaks. something something the evils of html. other special characters like <> might have the same issue but few links use them anyways

Example of bug: Should link to user 617, & breaks, instead links to user's own account if they have one
Another example of bug: Should link to a specific forum thread, & breaks, instead links to general forums

Took me a while to figure out how to fix this one but it should be good now!