Bold Thread Title

When I reply to a thread that wasn't bolded - meaning there were no new posts in it since my last visit, right? - it becomes bold - meaning there is a new post?

It warns me of a new post, even though it's mine?

Correct. It does the same here and is stock vBulletin behaviour so we'd be unable to amend it even if we felt a need. However, as Mr Gates would say, it's a feature not a bug.

Why did I even post it? :banghead: :laugh:

Probably to see if the title was bold when you'd posted a new thread? :p

Oh, I forgot to check that!
Does it? Or do I have to start another thread to check? ;)

Yes, it does indeed :) hehe