Cant join a server that I just typed in

I typed in a server that i had just found on PlanetMinecraft, so I opened Minecraft expecting to join the server after i clicked on it, but it came up,"Could Not Connect to Host", So I tryed it on a server I had on thenlist before 1.5.1, and i joined, but my connection, if you hold down Tab, was a red bar. Is it just my minecraft?

Steps to Reproduce:
1. Find any server that you havent joined before 1.5.1
2. Type into Add Server the I.P
3. It should say couldnt connect to host