Navigator 6 can't find the built-in GPS-receiver on iPaq hx2790

I've recently got an iPaq hx2790b and some Tom Tom Navigator 6 software and I decided to give it a try tonight. I was prepared for some minor troubles, but that was unfortunately not, what I experienced.
After a smooth installation og Navigator 6, I - without having made any changes at all on my iPaq - could not get Navigator 6 to cooperate with the built-in GPS-receiver. It's just saying "No GPS-unit" (translated from Danish).
I've tried several GPS-configurations in the "Settings-menu" including: "Program GPS: None, GPS Hardware: COM 1 (or COM 2)". I've chosen "Other NMEA-GPS" and the different COM-ports in Navigator 6 unfortunatly without any luck. I've read that the hx2790b should be compatible with Navigator 6 on a few forums - including the one of HP - eventhough the hx2790 is not listed on the list over compatible devices from Tom Tom.
Do you have any idea, if I have a chance to make this work?

I hope my post is readable. My English-skills could have been better.

[mikealder]

Your English is fine - Where have you read the 2790 has a built in GPS chipset? As far as I am aware there is no GPS hardware in the 2790, to use it for GPS based navigation will require either a Bluetooth GPS receiver or a CF GPS receiver to fit in the CF slot - Mike

[Derekh]

Stefan
The 2790 is compatible with the tom-tom software but as Mike say it does not have an inbuilt GPS receiver.