Moderation bug for some users?

WP 1.5
I have an amount of registered users on my Blog, they are all LEVEL 2. But one user, no matter what he writes, has to be moderated, even there are no Words on the Blacklist, and the user started the thread and already wrote 3 comments there. Still i have to moderate him. Others are free to write, but this one not.
Email Obfuscator (plugin) is active. and another “Last – Comment for Post” viewer, developed by myself. But none of them interact in any way with the moderation queue