How to connect to the internet using GPRS bluetooth?

I have setup the bluetooth device on my laptop, have also setup the required
pairing with my celular phone. I am able to connect to the internet on my
phone using GPRS, so I know the phone works.

My problem is the phone now (it had worked once before) does not provide any
NAP service so my notebook cannot establish an internet connection through
bluetooth/GPRS connection.

Is the problem related to my handphone, or a security setting on my
notebook? I use Windows XP Pro SP2 (all updated), Kaspersky AV, Windows
Defender 2. Any help is greatly appreciated.