From the .plans:

Quote Originally Posted by snikkel
:: 11-Jan-2009 20:16 GMT (Sunday) ::

We experienced a temporary misconfiguration on one of the full proxy servers
in the network yesterday. This had the undesirable affect of notifying clients
and personal proxies that the OGR-NG contest was closed. This is not the
case. Clients and proxy servers that connected to this server may need to be
restarted in order to continue working on the OGR-NG contest. We apologize for
any inconvenience this may cause.
Could be related.