I've been having problems with any post/category that contains the word "blog". I.e. /blog/archives/2005/12/30/blog-post would bring back a WordPress 404 error even thought it does actually exist. Likewise /archives/category/blogging/ returns a WordPress 404 error, but all other category archives work perfectly.
I did not have this problem with WordPress 1.5, I've even tried using my WP 1.5 .htaccess directives with WP2 but no joy.
My ReWriteBase is /blog/ - is is just a coincidence, or is there some kind of bug being introduced by WordPress 2 permalink handling that is stopping any of my archives containing "blog" from matching correctly.
Everything worked fine before the upgrade to WordPress 2.