[p38fln]

I'm on Sprint's unlimited plan as well with 6.1. My PC runs windows Vista. I used the Internet Sharing app on the PDA to make it work - I've been able to stay online for hours wih no issues. You might want to try re-running the Vision setup (Phone options - Services - Internet - "Client Initiated IOTA START") this has cleared up a few odd issues I've had in the past. My internet setting is just #777 with no user name, password, or anything. Are you roaming when this happens? I get some really, really weird behavior sometimes when roaming.

The instructions posted above for internet sharing seem to be a lot more complicated than what I did - I didn't even have WMDC installed on my computer. I just opened Internet Sharing, hit "connect" and plugged it in. About 30 seconds later, the PC showed an active internet connection. Not sure if Vista already has some extra drivers or capabilities to make this work, though.