whats this mean?

[benkillin]

Warning: ob_start(): output handler 'ob_gzhandler' cannot be used after 'URL-Rewriter' in /home/seriousc/public_html/header.php on line 2

I dont have the code, but it pops up every once in a while on www.seriouszone.com (more specifically, the file system) it goes away if you refresh the page that it appeared on.

[Weedpacket]

Their server is using URL-rewriting (turning visitor-friendly URLs into server-friendly ones) and at the same time they're trying to use gz compression on the pages they serve to reduce their size. Apparently you can't do both at the same time.