So, a day ago I added a server,
http://www.gametracker.com/server_info/94.190.187.207:25565/
At first, it did work as intended, but then it started showing "dead" at some moments. I must say, the server maintains a really high uptime rate, the only thing being that there is a restart every two hours, but in 2mins max it is back online. As I see, in the last 6 hours it is being reported as "dead", but I can guarantee that the server is running, there are non-local players ingame, the router is not blocking any ports. The config file is properly configured. Help?

Hello,

You may want to try whitelisting the scanner IP's listed in http://www.gametracker.com/forums/forum.php?site=1&thread=42545

The scanners are timing out when waiting for more data from your server.

Really strange...
From the server machine, it was possible to ping via cmd some ip-s, other not, simply timed out request.

All the ports are forwarded by default... :/
I doubt it that a firewall could be blocking the said traffic.
Edit: Adding a server-ip variable seems to have done the trick, we wait now to see if it goes down again.

So, server-ip= has caused some trouble, so we changed it back to null.
We also set the query port to 25565, and after deleting and re-adding the server in your list, it worked, for some 10 hours. Now, it is again offline, but the server is running and nothing has changed?

Hello,

At the time of posting, your Minecraft server appears to be running. As Burn mentioned though, the server is not completing the stats request. I would suggest trying the following:

1. Review your firewall configuration as Burn has mentioned.
2. Review your installed mods - something could be altering the stats result.

Best regards.