I have my Nokia 9300 working for Bluetooth Internet connection and it does rather well. It did take me a few tries before I got it working properly:

In SETTINGS->CONTROL PANEL->PHONE my settings are:

Supported Profiles: DUN, FTP, OPP
Network type: GSM/UMTS

In SETTINGS->CONTROL PANEL->CONNECTIVITY->CONNECTIONS->{PHONE}

My Connection type: is GPRS