WP 1.5.1.1 RSS Feed Issue

I’ve discovered an RSS Feed issue with WP 1.5.1.1

The site this is at is http://osnewspodcast.com/

If I go to http://osnewspodcast.com/wp-rss2.php, then I get the feed just fine, but if I go to http://osnewspodcast.com/?feed=rss2, I get the following error:

Warning: Cannot modify header information – headers already sent by (output started at /home/content/a/d/r/adrianbacon/html/index.php:44) in /home/content/a/d/r/adrianbacon/html/wp-rss2.php on line 50

This is a virgin install of WP 1.5.1.1 that I just installed last night, and I haven’t changed anything. I’ve noticed that the rss feed embedded into the HTML HEAD points to /?feed=rss2 and not wp-rss2.php, so this is a problem for the ping services…

How do I fix it?