UGS Problem

Hi,
We're small MSO in DK, and I've been playing with docsis 1.1 UGS Service flows to control our QoS for SIP. I'm controlling UGS SF by IP-address.
The issue - If a SIP call is initiated from "inside" the UGS SF isn't activated, but when it's initiated from "outside" it works okay.
The IP match is okay in both cases, but in the first case the call is placed in the default SF.
We have two different CM's types, and the problem is the same for both..

Anyone out seen that before or have any ideas? (I'll get into details if nessesary)

/Claus