GSM off but GPS on?

[Marten PPCGeeks]

If I switch off the GSM / mobile phone (for example using the comm manager) somehow I can't get an GPS signle either? After swithing off the mobile phone transmitter my TomTom 7 can't find a GPS devide?
In the car while I use my HTC touch HD with TomTom (and need the signal of the build-in GPS receiver), but i don't want to have / receive any incoming calls! But the GPS seems to be connected to the GSM?

Anybody any idea's what i could try to receive GPS signals Without receiving inoming calls?

(I did try but could find this subject / problem in any thread before, my appologies if I have restarted an old issue. If I have, please redirect me to the solution)

[bonesy]

You need HTC GPS Tool search google to find it.when you have it run and should auto set up ypur gps.As standard its set up on the wrong port :/ it needs to be on COM:4