Browsing the internet using PalmOS and GPRS on N6600

Here is the problem that I have.
I have a N6600 from London UK - Vodafone
I have the following settings on my phone for internet connection using
GPRS
Vodafone internet - used for internet browsing using the browser in the
phone, java midlets etc.
Vodafone GPRS - used for MMS ( though I have never used this)

I am able to connect to the net using 'Vodaphone internet' GRPS setting
using the browser on the phone and also using some MIDlets that I have written for my phone.

I also have a PDA Sony NX70V with PalmOS5

I am trying to connect to the internet using PalmOS on the PDA ---->
infrared --> N6600 (GPRS)

But I am not able to connect.
I start up the application - Connections, Modem ( connect through infrared)
and then I have configured Networks and Connections on my PalmsOS but when
I click on Connect on the Palm OS I get an error saying modem not found.
On my the Modem application reports 'connected' but there is no GPRS
activity???

Any ideas?

Could someone give me the setting that I have to set up on my Palms OS ?
I am allready using COMA on my PDA for this connection, but I dont know the
version of COMA and this version does not have an option for N6600.