I'm having the same experience with my RAZR as with my Bionic. I plug the phone into my PC via USB, then go to Settings > Wireless & Networks > Tether & Mobile Hotspot > USB tethering. My Win7 PC then installs drivers automatically, yet my connection sticks on "Identifying..." and never works (can't assign IP?) I've installed motorola's USB drivers, and tried without them installed, and have run out of ideas. While "Identifying" the network, my network windows freeze and can't be closed until I unplug the RAZR. Google has been of no help.
I've read over and over how Bionic owners simply plug the phone in, enable the native USB tether, let windows install the drivers, and it simply works... Can you guys share your experiences with this native usb tether, especially if you have/ have had the same issue?