I haven't been able to connect since the last wednesday or so (cvs update just hangs until it times out).
If this persists, someone else will have to check in my SRE patches...
You may need to force protocol version 1. You can do this by adding/modifying a stanza in your .ssh/config file:
host cvs.python.sourceforge.net Protocol 1,2
unfortunately, that didn't help. at least not at once; things started to work again after we rebooted the computer (for other reasons).
linux gremlins, most likely.