Please explain ...
• Only one or two forums (Pit Road, Line-Up Board, etc.)?
• Only some posts?
• Just cut off in middle of page?
Would you be able to send me a screenshot?
One thing it might be is if you click on the main forum topics (Pit Road, Line-Up Board, etc.), then only that forum and it's sub-forums will show up.
Also, try clicking the link that says "Delete all board cookies" at the bottom of the page.