I figured it out. I had access to the server logs, but they were still returning 200 ok and looked fine. After disabling plugins, it looks like WP-reCAPTCHA was conflicting with bbpress’s reCAPTCHA. I should have realized that, haha.
I’m running bbpress 1.0.2 and the latest WordPress 2.8.2. User and cookie integration is working perfectly, but I’ve been trying to do a “deep integration” so that I can use WordPress’s templates.
Whenever I try to include “wp-blog-header.php” in the config file like in past installations of bbpress, my forum spews a blank white page at me. I *know* that it’s finding the header file, because if I purposely change it to the wrong path, it’ll spew out an error at me.
Just to try it, I’ve also attempted to include wp-load.php, wp-config.php, as well and have ended up with the same blank page every time. At first I suspected it may be a permalinks issue, but even after disabling that the blank page persisted.