BuddyPress.org

Hi, the website is http://scorephoria.com
I designed the site for my boyfriend and I am having the following trouble with it:

1.) When I go to reply to a topic I am always taken to a 404 page.
2.) The reply still posts after you navigate back to the forum topic page.
3.) Also 404 pages will often appear when a page is loading. The 404 page will show up until the site is completely loaded.

I set up an account for anyone to see for themselves
username: test
password: test

Could anyone please help me out with this? I saw somewhere that it could possibly be a memory issue? I have very little knowledge of scripting and any suggestions at all would be appreciated!

Thanks in advance!