Blank wp-comments-post but comments work on fresh install

site: aetheric-shade.org/blog (please forgive the nonlinkyness, I’m new here ?? )

This is what happened: After I converted my site over from b2evolution using the b2evo2wp script, I noticed that comments were broken. Every time I try to test out making a new comment, I am always redirected to a blank wp-comments-post.php, so I tried reinstalling WP to no effect (leaving my database intact). I also tried reinstalling the theme I am using (MX4 theme), and deactivating all my plugins (RumMovie. SpamNuke, IImage Browser, Miniblog, WP-Amazon, and Plugin Manager) also to no avail.

I emptied out my database and did a truly fresh install with none of my old entries or anything – and comments worked. I then tried importing my old b2evo posts instead of uploading my saved WP database, but then I get the “Header already sent” error.

Might there be something else I could try to keep all of my entries but also have comments work?

Thanks in advance. ??

Edit: I read in the codex about the Header already sent error, tried uploading a fresh config.php file, but that did not work either.