asterisk users - Oct 2005 - Incoming Calls causing Protocol Error (6)

Hi Everyone,

Got a setup as follows:

Telco ----> Siemens HiCom 300E <----> Asterisk1 <----IAX2
Trunk---->
Asterisk2 <----> Siemens HiPath 4xxx

The solution works except for one problem. Incoming calls from the telco get
redirected to the Asterisk1 box with the correct extention, only if there is
a callerid set on the call, the Asterisk1 box drops the call (it doesn't
even get to asterisk) with a "Unable to handle pre-handled call" and
"Protocol Error (6)". If you disable your callerid on your phone and
phone
again via the telco, it gets passed through. Asterisk1 reports "Accepting
overlap call from '' to '5804'"

Currently using ECMA.1 on the Siemens HiCom 300E, and Asterisk1 is setup
using euroisdn. I am using Asterisk 1.2.0-Beta1. Asterisk1 is running as
pri_cpe as well as secondary sync source.

Any ideas on how to fix this problem?

Would it be better to change the switchtype to Q.SIG on Asterisk and on the
Siemens HiCom 300E ?

Or am I missing a configuration line?

Thanks in advance.
Doug.