can not parse name and number from sip header

[Ret]

Hi
I have "successfully" connected an OXO to an Elastix 2.5 Server (Asterisk+FreePBX). The OXO considers Asterisk as a Public trunk and calls coming in are treated as from PSTN.
Everyhing is fine until Asterisk reports this error

ERROR[19982][C-00000d82]: sip/reqresp_parser.c:830 get_name_and_number: can not parse name and number from sip header.

This error appears after an extension from Asterisk tries to dial a call to PSTN with prefix 9 (They can still call extension on OXO)

I repeat.... all settings work ok, but there's some specific situation that triggers the error.
Any help? thx!

[tot3nkopf]

Check related asterisk trunking configuration posts on this forum. It has been debated many times.
And by the way w/o a trace we cannot know why Asterisk complains about the SIP header sent by Alcatel.