Good luck to you.
I say this to start because almost every sandisk image in the I-Opener community is based off the original hacked V1, which did not have this feature.
The only alternate isp capable v1 images actually using the default I-Opener browser had to be hacked using the QNX command-line for a specific phone number and ISP login, and if most of this is over your head, doing that might be difficult indeed.
But at least you're looking in the right direction.
Seeing as the service is shutting down support, you may get lucky, and happen upon a fellow disconnected owner with the upgrade.
Stranger things have been known to happen. =)