My server not showing up on list? (server us1313)

[down167 2]

for some reason my server isnt showing up on my server list, shows the same for my friends and we have alot of very good and rare items on there in tents.

How can i find out if the server is down for maintenance or if its just down forever?

[hybrid86 10]

im having teh same problem i can join with the IP address but i no one can find it in the list