Wait for your DNS stuff to fully propagate. It changes in DNS do not reflect immediately because there are a lot of DNS servers. Also, DNS follows some kind of hierarchy. Just be patient and wait a little longer.
If you cannot wait and you are using Linux or other *NIX OS, then just hardcode the frih.net IP address and your subdomain to /etc/hosts. Of course, this should be just temporary; just for checking if the subdomain actually works. I don't know how you can do this in Windows but you might as well try searching the net to check if it is even possible.
I hope this helps.
usually its not more than 5 minutes,subdomain is very fast to work
Nothing's still happening. Is there any problem with server 2?
Your problem might have something to do with Server 2 accounts being moved to Server 3: http://www.frihost.com/users/Bondings/blog/vp-99580.html
I haven't added nor removed a subdomain recently after the news broke out so I don't really know if your problem is related or not. Anyway, you might want to contact Bondings regarding the matter.
still not tested, but usually sometimes quick, sometimes slow