No IAX2 peer can register

Hi,
I have a Asterisk 1.6.2.7 running on ubuntu server 10.10 64 bits with FreePBX 2.8.1.4. Yesterday I manage to setup receiving fax with IAXmodem and Hylafax. Everything was working fine. I had to reboot the server. Now no IAX peer can register with the server. I tried with IAXmodem (Installed directly on the server) witch was working fine before the reboot. I tried with my softphone, no luck… The funny thing is there is no log whats so ever generated by my failed attempts. I use tail -f /var/log/asterisk/full and when I try to register no new lines appears. There is no firewall rules on the server:
root@PBX:~# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

The IAX module is loaded on the asterisk:
PBX*CLI> iax2 show peers
Name/Username Host Mask Port Status
698 (Unspecified) (D) 255.255.255.255 0 UNKNOWN
697 (Unspecified) (D) 255.255.255.255 0 UNKNOWN
2 iax2 peers [0 online, 2 offline, 0 unmonitored]
What am I missing???