I recently setup an outgoing trunk group on my OBi202 using the excellent directions supplied by ianobi here (http://www.obitalk.com/forum/index.php?topic=6924.msg44201#msg44201). I tested it thoroughly, and everything worked great. Later however, I discovered that several calls were missing from my Phonepower call log, which is first choice for the tg. Eventually I realized what was happening.
To test the trunk group I had to place 3 calls. To facilitate this, I temporarily set PHONE2 to use sp1 (first choice in the tg) and placed a call to my cell phone. Next, I placed a landline call to PHONE1 (via sp1). Finally, I hookflashed PHONE1 to place the third call over CallCentric. The only outbound calls in the PP call log were the ones that didn't go thru the trunk group (i.e., the ones temporarily routed out sp1 from PHONE2). At this point I realized I was dealing with a signalling problem, and tried various settings until I nailed it. The "magic" setting is:
Service Providers > ITSP Profile A SIP > X_UserEqPhone (must be checked)
The above assumes the PP trunk is on sp1. Note that this was only required for the Phonepower trunk; CallCentric recorded call log data fine without it.