Having lots of issues with USB tethering in Vista

[Half Decaf]

I use vista --, however, I usually use PDANet to connect to the Verizon network; I also use Bluetooth PAN for tethering, If I want to go wireless for some reason. No major problems here with either one. It is true that I frequently have to reconnect my PDANet to Verizon *once* in the day - this disconnection usually happens within five minutes into the first connection (However, unlike your situation, PDANet will clearly say that my modem is disconnected) Anyway, after that first drop and subsequent reconnection, my connection is then solid for 7 - 8 hours straight. A weird phenomenon, but I have learned to live with it - I have attributed it to the Verizon network. I see you are on Sprint, so your connection issues may lie with them.