Bluetooth Serial Port Discovery

How do I make the Microsoft XP/SP2 Bluetooth Stack advertise a Serial
Port Service?

I have a PC program which communicates using a COMx port, and a mobile
phone program which looks for the serial port service advertised by
the PC and connects to it.

Using the Widcomm Bluetooth stack this works fine - the phone sees the
Serial port service advertised by the PC and can connect to it.

Using the Microsoft Bluetooth stack the PC doesn't advertise the
service, so the phone can't connect to it. Although the Bluetooth UI
on the PC side is showing that incoming and outgoing COM ports are set
up, they aren't being advertised in the SDP (Service Discovery
protocol).

Is there a programmatic step that needs to be taken on the PC side to
get the incoming serial port properly advertised in SDP? (currently,
the PC program is coded to use the COM-port API only, and I'd prefer
to keep it that way if possible)

Or is the Microsoft Bluetooth stack serial port simply not working
properly?

TIA, John

> How do I make the Microsoft XP/SP2 Bluetooth Stack advertise a Serial
> Port Service?

Doh! It seems the Serial Port Service *is* advertised, but only after
the COM port has been opened in the PC program.

This is different from the way the Widcomm stack does it, so had me
fooled for a while