[JKT]

As far as I am aware it isn't buggy. It just removes the first word or series of words that are the same in more than one tab. E.g. "MacWorld" if you browse to more than one of their pages at a time. Or the forum titles here. Simple as that.

If you check the behaviour again, does this sound like what it is doing? If it isn't then you are experiencing a bug, but the reason isn't because of the default behaviour.

Fwiw, I don't know of any way to remove the behaviour completely.

Edit - note that this means that titles can be trimmed even though their from two different domains. For example many Mac related sites will have stories starting with the word "Apple" so you won't see it in the title of the tabs when you are viewing more than one at a time, even though they originate from different sites.