Minecraft server port is open but other's can't connect to it?

I went on a bunch of websites where they tell you if your port (25565) is open, and they all came out as a yes, but my friend can't connect to it.I've port forwarded, and it works for me when I do "local host". I have a craftbukkit server, if that makes a difference. My brother can connect to it using the internal ip, but my friend can't connect to it with my external ip or my internal ip. Can someone please tell me what's the problem and how to fix it? And no I'm not giving my ip to anyone so they can try.

Ps. It's not on my friend's side, she can connect to other servers, but not mine.

FreezingJets

Maybe your public IP has changed? Re-check what it is:
http://www.whatismyip.com/
and have you friends try again. If other sites show the port as open, then it is… Only reason for someone else to not connect over the Internet would be a wrong Ip address they are using, or they are not specifying the proper port when connecting. This all assumes your server is accepting "outside" users to connect/login.

Adrian