what i did was.. delete the .htaccess file and reuploaded it.. and its working now..
I figured out that the problem happened 2 hours after everything was working.. ie hack installed..
The forums have been up for longer then 2 hrs with hack functional!
So hopefully it seems ok and stable with no errors!
Feel free to add the link to the "archives working" on the front page! to make people install
Once again thank you!