The patch KM mentioned should help if you're running secondary.
If you're running a primary connection, then there may be something else causing it.
If you have a firewall, the firewall may think you are being attacked while loading the roomlist on primary, due to a lot of packets from 1000s of IPs. it's possible that the firewall kicks in after about 10 rooms. If you're running a primary connection, and have this problem, you'll have to look for some option in your firewall to disable this... If you're running a secondary connection, then don't worry about this, just get the patch