its a known issue, it only says that since 1.5 because for some reason it replaced the "outdated" message you would get when the server is a lower or higher version (1.4-1.5 etc)
If you have 1.5 i would suggest downgrading if you want to join the 1.4 servers.
Thanks to Impact. for the avatar and Signature!
Quakelive.com
Havent played much ik but I will be playing!