Problem with Emails in Comments

All commenters on my blog have to enter a name and email address. However, for some reason, the email address never gets entered into the database. I think ever since I upgraded to WP 1.5, all the values in the user_email table are blank, and I can’t figure out why.

This is just a minor thing, but I’d really like it to work properly. I use SpamKarma 2.0 and referrerKarma, but even when those plugins are deactivated, the emails still never make it to the database. Is there a plugin stripping out the email addresses before they get to the database, or was there a change in naming conventions? I checked the database from the phpMyAdmin and the field name still appears to be the same. Please help!

This has been going on for a while now, and it manifested itself when I only had those two plugins installed. I understand that this seems to be a rare problem, and wanted to know if anyone had heard of it happening to anyone else, or what it might be caused by.