I don't know if there's a better place to submit this but I was noticing 404 errors on a couple of images (loadingAnimation.gif and tb-close.png) from the thickbox media uploader on the p2 front page new post form.
By default the media uploader uses relative paths starting with ../ because it runs inside wp-admin/. The fix, since WP 2.8.4 is to override the location inside p2's post-form.php :
===================================================================
--- post-form.php (revision 13036)
+++ post-form.php (working copy)
@@ -1,4 +1,8 @@
<script type="text/javascript" charset="utf-8">
+ /* properly reference thickbox images */
+ var tb_pathToImage = "./wp-includes/js/thickbox/loadingAnimation.gif";
+ var tb_closeImage = "./wp-includes/js/thickbox/tb-close.png";
+
jQuery(document).ready(function($) {
Oh also, I'm using WordPress 3.1-alpha from the SVN trunk and a SVN checkout of the p2 v 1.1.5 tag/branch.