This is such a strange problem: I tried testing the WordPress 2.1 that's floating around on the testers list and decided it isn't for me. However: I backed up both my WP installation and my database before doing this because I planned on rolling back to begin with.
Now the strange part: after blowing away the WP directory, rolling back my database and then re-installing the latest 2.0.4 public version (and now 2.0.5 RC1 just to see if I can solve this problem), I and other testing friends reliably get a blank page whenever trying to access the main page, any posts or other pages:
Upon a refresh however, the page or post renders perfectly. But then, surfing to another page/post exhibits the same blank page. Refresh, rinse, repeat.
Any ideas what could be going on here? I appreciate any help.