I forwarded ports, using the port checker tool TCP/UPD (or something) is forward propertly , I can see my server in server list and when I click on it, it connects for a few moment, then says Failed to connect, the server is prob down! How do I fix that? Using http://www.minecraft.net/play.jsp?serve ... port=25565 , theres red text saying I cannot connect this way anymore!
If someone connected to your server, but you can't, something is prevent you from connecting to your own server. Probably a firewall? I highly doubt it but... I don't think they joined, but they failed to Join. Or that was you.