My minecraft server is red.forumlight.com using the port 25565, but to log on you only have to type red.forumlight.com
The server is Bukkit so there should be no problem. Why can't I add my server? I even have a website up for it.

Your server isn't configured to respond to scan requests.
In order for GameTracker.com to successfully scan your Minecraft server you will need to install either the CraftBukkit or Canary plugin.
CraftBukkit Instructions [Offical Site]

Install CraftBukkit
Get the CraftBukkit Plugin
Put the CraftBukkit Plugin in you servers "plugins" directory
Edit "server.properties" and set the "server-name"
Restart your server or reload the plugins with "/reload"

Canary Instructions [Offical Site]

Install Canary
Get the Canary Plugin
Put the Canary Plugin in you servers "plugins" directory
Edit "server.properties" and set the "server-name"
Add "MinecraftViewer" to your plugins in "server.properties"
i.e "plugins=MinecraftViewer,CuboidPlugin"
Restart your server
This can be your problem.

My server is already a bukkit server, so that can't be the problem.

Is this a minecraft classic server? If so, it does not support scanning.

my server did not found on gametracker

rinks1484 wrote:
my server did not found on gametracker
You will need to add it so that it is found in the server list.

It is not classic, its 1.8.1 the newest update.

Install the minecraftViewer plugin for craftbukkit and change to plugin query port in plugins/MinecraftViewer/config.yml to 25566.

Create a server entry with the gt form and use the following ports:
25565 and 25566, i have the same problem, you cant use in minecraft the same port for different things

greez - eiermann
PS: sorry for my bad english