comments won’t recognized name/email

my blog is at andyschest.com/wp
and it won’t accept comments from non-registered users.
Even if someone fills in their name and address they get this message:

Error: please fill the required fields (name, email)

I had WP version 1.2 and used jeff barr’s anti-spam code:
http://www.syndic8.com/~jeff/blog/index.php?p=103

and everything worked fine. When I upgraded to 1.5 is when I started having problems. My webhost is dreamhost and they have something called a “one-click install” which I used to upgrade to 1.5. I believe it essentially just overwrites all existing files and uses the same database. Anyway, after I upgraded to 1.5 the comments no longer worked.

I had also installed Kitten’s Spaminator which I thought might be the problem, but even when I de-activate the plug-in the comments won’t work.

I also thought it might be a theme problem, but I’ve switched to various themes with no change in the comment situation.

I’m not very technically savvy, but I looked at the various files involved (wp-comments.php, wp-comments-post.php) and everything seems to be in order.

I’m not sure where to look to find the problem or how to solve it.
Any advice greatly appreciated.

Thanks!