asterisk users - Oct 2008 - Caller ID service and the ethernet stucking

Hi All;

We added the callerid service on our telephone line, once that done, now when we
call to the Asterisk PBX or we need to place outside call via the digium (zaptel
channel), the PBX got a problem in the network, and we become not able to reach
it, this stay for a while of time (about 5 min) and then it come back reachable.

I did not do any thing when the callerid service added by the telecom service
provider, and I am surprised why this callerid service effect on the ethernet
port?

Did any one face this problem?
My asterisk version: 1.4.19.2
My zaptel version: 
Zapata Telephony Interface Registered on major 196
Zaptel Version: 1.4.10.1
Zaptel Echo Canceller: MG2
INFO-xpp: FEATURE: with sync_tick() from ZAPTEL

In the /var/log/asterisk/messages, I did not find any message that help (warning
or error).

Any advise? Did any one face such problem? 
The PBX located in KSA.

Regards
Bilal