Usenet Explorer

In the newsgroup view, there is an aqua-colored oval next to some of the messages in the 'flag' column, specifically ones that have "2.0" in the subject.

I've gone over every option in UE and don't have any watch or kill filters specified, so I was wondering what the heck that is and how do I get rid of it?

check the rightmost check box in the quick filter bar (view menu->quick filter), it will switch to the find bar, clear all the fields there and uncheck the check box to switch back to the quick filter bar, newsgroup views show matches to the find dialog bar whether it is shown or not.