WordPress MU

Well now my site is up and running. I can login into my adminpanel without problem.

But when I register a user and got the activation-link trough mail, but it just doesnt work. Before this I tested to have the blog as domain.com/blog but now I'm using blog.domain.com (subdomain) and I cant activate it.
It become this when I try:
[code]
The requested URL /wp-activate.php was not found on this server.
[/b]

What to do?
Btw, if someone likes, please ad me to MSN:
kristoffer_nahlstedt@hotmail.com

I might got rewards for the one who help me!

Check the following: wp-config for $base, database tables wp_blogs and wp_site match the URL you're using.
Debug wpmu-settings.php to figure out where it's going wrong. Use print, print_r and error_log to dump variables, especially $blogname.

How do you print, print_r and error_log to dump variables, especially $blogname?

We write print statements in wpmu-settings.php?

Yup, open wpmu-settings.php and add "print $blogname;" in various places.

Check your .htaccess file too!

I am helping Nachen. One concern is his webhost directory structure. He has a .com domain name. They place a folder for each of his domains. MU was installed here. /hsphere/local/home/nahlsted/domain.com/

What I am concern is whether this is the root? It should be since it's the only way you can access it through domain.com URL. Everything runs well (no error log), except his user activation doesn't work at all.

wp-config for $base = '/'; database tables wp_blogs and wp_site match the URL you're using which is domain.com, with path being /.
VHOST = YES
SUBDIR = NO (?)
VERSION = r616 downloaded through svn tortoise 29 June

Print statements were added into wpmu-settings file, but I do not see any errors. How do I take note of blogname appearing?

Another note, subdomains doesn't seem to be working.
A Fatal Error should be seen, but instead I was being directed back to the main MU page (domain.com) when URL subdomain.domain.com was accessed.

Nachen has noted that Apache as been set. Seems to me that mod_rewrite is not working.

That's really strange. When you visit host.domain.com is $blogname equal to the hostname?

Edit wpmu-settings.php and after the chunk of code that sets up $current_site and $current_blog either error_log() the variable to a local log file or mail() it to yourself.

I just setup a vhost site and it does work: http://donncha.dashdotslash.org/ (this url will disappear, don't worry if it's gone!)