I stand corrected. I just looked up F225 in the manual:
F225:..."If the PRI span is used for outgoing calls, pilot table entry 1 is used for outgoing Caller ID, as well. Because of this, pilot number entry 1 should always be programmed with 10 digits....
Note: An extension’s Caller ID number setting (see “Function 31:....Extension definition and routing) overrides the pilot number’s Caller ID information set here."....
F31:...Caller ID — Used for outgoing calls to identify the extension and for callback to the specific extension or another extension nearby. Each entry must be valid and 10 digits in length.
If there is no entry here, the PRI pilot number will display as Caller ID....

This may not help but but worth a try: disable PRI Caller ID Forward in F166. I've had two carriers that this cleared up some outbound issues with.