BLuetooth modem fails to complete a data call - 'No carrier'

I have a Dell Lattitude D620 with the internal Dell wireless 350 bluetooth module - running the latest 'Dell' Toshiba drivers.

I use bluetooth to link to a mobile phone 'nokia' then setup a virtual com port to the phone, i have a remote data collection application that will then dial to our remote modems and collect data using the modem of the mobile phone.

 

This process work perfectly well on my old laptop "a dell inspiron" using a usb bluetooth device, but fails to work on the new laptop - same software same phone.  

The connection from the new laptop and 350 to the phone works fine and i can explore the modem within the mobile phone using 'AT' commands but when i try to dial - the modem returns with the prompt "No Carrier" .

 

Strangely the old laptop would dial ok using the same mobile phone ?? the only difference between the two is the bluetooth module and the drivers - the new setup D620 used the 350 and Toshiba drivers where-as the old setup used a DLink usb bluetooth stick and Widcomm drivers.

 

I think the problem is the toshiba driver not sending some initiation or security code to the phone - but thats my latest thought after trying so many other things to fix this problem.  What is the widcomm driver doing that the Toshiba driver is not??

 

If anyone has any thoughts or experience with regards to this problem please help.