Hey
Well, the server has been running for the past 24 hours, although before that I did a reboot and it was down for an hour or so, it could be that you tried to log on then? Or, as Gundam said, it could be something to do with the login servers you're using?
(Oh, as a sidenote, the new RAM hasn't actually been added yet, I've ordered it though and am still waiting for the server provider to install it.
)