Server Full

I'm being told this all the time when playing Warhawk. I've adjusted my filter so I'm only going into games which suit my rank.

I've read the portforward.com article. Is that what I really need to do in order to avoid getting the "SERVER FULL" message?

Or is this something that will be ironed out in the near future by Sony?

Or are the servers just slow in updating their information and really are full instead of the 20/32 that they are showing?

Thanks for the help.