SIP Trunk problems, calls In/Out, host=dynamic?

Hello,

I am trying to set up a pennytel sip trunk, outbound calls were never a problem and worked perfectly with the standard settings:

PEER Details:
host=sip.pennytel.com
secret=2XXXXXXX
type=peer
username=61XXXXXXXXX

Reg String:
61XXXXXXXXX:2XXXXXXX@sip.pennytel.com/6XXXXXXXXXX

After days of searching I finally got inbound calls to work by creating a custom context to get the DID from the SIP header, and changeing the trunk settings to:

PEER Details:
host=dynamic
secret=2XXXXXXX
type=peer
username=61XXXXXXXXX

Reg String:
61XXXXXXXXX:2XXXXXXX@sip.pennytel.com/6XXXXXXXXXX

Note that these are in the PEER details section, pennytel seems to ignore the USER section entirely.

The problem is that if the host is set to sip.pennytel.com, I get outgoing but not incomming, if I change it to dynamic I get incomming but no outgoing (sip shows as registered but not online).

Also, I have 2 pennytel trunks on this system, and setting EITHER trunk to host=sip.pennytel.com breaks incomming calls for BOTH trunks.

Any help would be greatly appriciated.