I know most of us are patched up to date but a friend is trying to update his client and it says unable to connect to patch server. He has restarted his cable modem, pc and Xsyon client to no avail.
I've had this happen if I quit the game without logging out correctly. If that is the case, it should fix itself in a few minutes. If it isn't, he could try the support link at the top of this page.
Could try connecting to the other patch server if it's only one he can't connect to. Beyond this, I would suggest contacting support. They usually respond in a timely manner.