Look for it in public_forum_summary.pl
It's the cell that will have variables like $last_author, $last_date, etc. The variables are pretty self-explanitory, so just look through that file, find the cell, and remove it. I can't be more specific than that because I don' have the template files in front of me at the moment. If you need exact instructions, you'll have to wait till prolly sometime tomorrow, hwen I get internet working in my dorm again and can look at the templates to answer it.
---Skorpion