WordPress MU

While clicking on the activation link sent in the mail I get an error:

WordPress database error: [Incorrect integer value: '' for column 'site_id' at row 1]
INSERT INTO
wp_sitemeta ( site_id , meta_key , meta_value )
VALUES ( '', 'illegal_names', 'a:7:{i:0;s:3:\"www\";i:1;s:3:\"web\
";i:2;s:4:\"root\";i:3;s:5:\"admin\
";i:4;s:4:\"main\";i:5;s:6:\"invite\";i:6;s:13:\
"administrator\";}')

The tables for the new blog are created but this error seems to be due to lack of integer value for site_id.

Anyone know what the problem can be or where I should start to look for it?

Forget it. It seems like this problem was due to some server settings.

This thread can be removed. Sorry.

I have same prob. What this means?
What exactly server settings get this error?
Please DO NOT delete this topic =O