Not that I know of. The funny thing, same thing happened some minutes, but that time, the subtitle had went on a trip down to the "Replies" box of a thread. I had clicked a link before I noticed, though, so I didn't have time to get a screencap. But that's the only two times it's ever happened.
With Firefox, just go Tools -> Options, and it's under the Web Features section.
With IE, it's... uh... somewhere. Yikes. I've never really realized how until now completely incomprehensible IE's option dialog is. Up until now I've only wanted stuff on the somewhat sane General tab.
Firefox just got a nice lift in opinion for me there. It's starting to creep up on me... ^_^
However, I have 800 people on one 2Mbit line, most of which is taken up with my downloading speed runs...
...and I never had anything like that. I once got some really odd formatting in which the user identity column became as wide as the post and some posts started going sideways rather than down...