Parking lot CallerID Prepend problems

Hello,
I have trixbox 2.6, freepbx 2.5.1.1, astrisk 1.4. I am having problems with the callerid prepend not working. I have ‘PK’ in the field, but when I test it, it doesn’t work. is there something i’m missing?
thanks,
-Aaron

has anyone gotten this working? or has anyone else had problems with this?