Odd errors when connecting to new servers.

Whenever I try to connect to a server my client freezes, waits about 20-40 seconds, and then says unknown host, EVEN THOUGH ITS NOT A UNKNOWN HOST. However, when I connect to the new starmine pvp server it lets me join after the freeze.
This is a odd bug, but the thing that has me puzzled is that when I play starmine, it doesnt even freeze. It only freezes when I connect to a server that hasnt been in my list for a while.
Im really not sure whats wrong, and I have found no help on anywhere else... so mabey someone here has the answer.

EDIT: mabey its just snow hacking my client so that I cant play anything other than starmine

But seriously, I don't use any mods, I use a vannilla client, so I have no idea whats going on.

You using the new IP? We have a new provider.

I get this problem too. What I found was the best way to fix it is instead of double clicking the server of choice, click the server you want to play on, then click join server. That should do it.

NOTE: If you double click and get that error, then try my method, it wont work. Log on to singleplayer then try my method again.

Sheep I have the new IP, but its still not working correctly.
And Aus, ive tried, it doesnt matter if I double click, press join server, or even try to connect using direct connect, it still freezes and most of the time wont let me in.

But again, the odd thing is, it lets me into starmine survival normally, and it used to let me into the old pvp server nicely. but the new pvp server is messed up, as well as any other servers i try.