PSTN lines working/not working after reboot (Sangoma A200d)

I’m having a lot of problems with getting my four analog lines to work.

First I’ll give you a overview of my hard- en software used :

Server : HP Proliant ML110 G5 (Intel Xeon with 6 GB internal memory, 2x 250 GB HDD (RAID1))
Telephonycard : Sangoma A200d with 2 FXO modules inserted (so, four analog lines with Hardware-EC)
4 external lines ; 3 lines from one provider (KPN Netherlands), bundled as one number and 1 line from another provider (Versatel Netherlands), mainly used for incoming faxes.
Operating System : CentOS 5 (2.6.18-128.1.1.el5xen), XEN kernel.
WanPipe version : 3.4.4
Dahdi version :
Dahdi-Tools version : 2.2.0
Asterisk version :

The problem :
Every time I restart the server, or just asterisk and wanrouter, it is the question which lines are working.

To explain it simply I’ve three states in which a line can be :

  1. When calling to the asterisk server (for example with my mobile phone), the server picks up the call, but no sound is heard.
  2. When calling to the asterisk server (for example with my mobile phone), the server picks up the call, sound is heard, but DTMF is not working (I’m using a IVR menu).
  3. Line is working perfect; the server picks up the call, sound is heard and DTMF is working. People get to an extension and can have a conversation.

So when I restart the server, sometimes line 1 is in state 2, lines 2 and 3 are in state 3 and line 4 is in state 1.
When I change NOTHING in the configuration and restart the server, line 1 and line 3 are in state 3, line 2 and 4 are in state 1.
These are just examples, every line can be in another state after a reboot. Sometimes all lines are in state 1 (nothing is working), and a very rarely time all lines are in state 3 (everything is working).

At this time of writing I’m running on 3 lines (lines 2, 3 and 4 are in state 3), line 1 is in state 2. Because it’s a live system (people are depending on it), I’m afraid to reboot it again, because it can take one to twenty reboots before everything is working ok.
And again: I don’t change a single file on the server before I reboot the server.

I’m experience this behavior since the first installation of the server back in April 2009. I’ve updated all relevant software (wanpipe, dahdi and asterisk) several times and completely reinstalled the server on a Sunday back in June 2009 (not my favorite waste of time on a Sunday).

I hope someone can give me a clue, because the only thing my boss does give me is a :imp:

With regards,

Jan Peter
The Netherlands