Asterisk Locks Up

I am trying to configure Asterisk using SS7 trunks. I am using Debian “Etch” Asterisk 1.4.18, Zaptel 1.4.8, and LIBSS7. I can get everything working correctly, however, if I reboot the computer, when I go to place a call from my SIP phone I get the following error when I press any number on the keypad(for example pressing 0 to speak to the operator ) this happens when placing a call from sip to a landline going out over the SS7 trunks.

here is the error:
{] sysenter_past_esp+0x56/0x79
Code: 40 54 00 00 00 00 c7 40 58 00 00 00 00 eb 14 89 50 44 c7 40 50 00 00 00 00
89 48 54 8b 44 24 08 89 43 58 5b c3 c7 00 00 00 00 00 <8b> 4a 04 89 48 04 8b 44
08 c7 40 0c 00 00 00 00 89 48 08 8b 4a
EIP: [] zt_init_tone_state+0x6/0x2c [zaptel] SS:ESP 0068:dd0d98b8

it appears to be a Linux EID error and the entire computer locks up. I didn’t get this error before I rebooted my computer for the first time, also I have tried asterisk 1.6 and I got the same results. Any help or suggestions is greatly appreciated.