Sounds like the "dash" bug, where if you post a link with a 'dash' in it on the page, the whole thing blows up...
I don't see a 'dash' per se, but it does look like someone posted a link with an 'underscore' in it. I don't know if that reproduces the same problems the 'dash' does/did.
I do know the "dash" bug was fixed for the Story Game viewer, but I don't know if it was for the forums...