Ha! I figured out the problem this page was testing and it wasn't title length. Well, I should say I figured out where the problem was but not how to fix it or why it happened. I ended up going over to the official Simple:Press forums and posted the problem there.
The fact that a user profile and/or signature file can hose up the entire page as well as the administration page to the point where an admin can't edit the profile at all is a Very Bad Thing. I hope they can figure out what happened.