Error while starting the listener for the SIP protocol

You will not be able to receive incoming SIP calls. Please check that no other program is already running on the port used by Ekiga.

What would be running on 5060?

01:05:39 Started Ekiga 2.0.12 for user ***
01:05:41 Set STUN server to stun.ekiga.net (Cone NAT)
01:05:41 Registration of *** to ekiga.net failed

Nothing in, nothing out... strangely it worked for one call and now not for anything, even the echo

01:16:03 Calling sip:500@ekiga.net
01:16:04 Security check failed
01:16:20 Calling sip:501@ekiga.net
01:16:21 Security check failed

To call my buddy that doesn't have his machine on... we connected before...
01:19:30 Calling sip:****@ekiga.net
01:19:31 Remote user is unreachable

I have everything forwarded, DMZ status on the IP, no firewall