@Rick - okay, ran both queries, and it seemed like everything was okay but after a few minutes ... Well, this happened:

http://www.meikin.net/issue1.png

BUT... When I run the queries again it says that 0 rows are affected.

I click on the forum to see what I can do...

http://www.meikin.net/issue2.png

Then, I go to click on the shown topic directly, to delete it, and this happens:

http://meikin.net/issue3.png

and when I click into the specific subforum, this is what I get:

http://meikin.net/issue4.png