Social for Buddypress issues


So I finally did a revamp of my website using bp-social theme you provide. Thank you!

I have a few questions/issues:

When I try to search something using the search box on the home page, I get a blank page. The error log says:

[07-Jul-2012 10:45:34] PHP Warning: Cannot modify header information – headers already sent by (output started at /home3/latinos3/public_html/lamsocialclub/index.php:2) in /home3/latinos3/public_html/lamsocialclub/wp-includes/pluggable.php on line 881

When I’m logged in, a new navigation bar appears on the very top, the one that has all the BP pages. I’d like to modify that, is that possible? If so, how?

Thank you,