I have a similar problem too! I reduced the size (width) of the forum to 480px to fit it in my website.
I don`t use frames!
Unfortunately the table with the latest news is much longer than the other tables.
You can take a look at
It seems to be impossible to change the length in the CSS, so I have tried to write the CSS commands directly into the HTML of main_last_discussions.html and main_last_discuss_cell.html, but it doesn`t work.
All the other tables are of correct size.
I don`t find a working possibility so I hope someone can tell me a solution.