I have seen similar issues with those drivers. I had an application talking to a SLC through a NET-ENI that would only work with one driver on the emulator at my desk, but only worked with the other driver on the real hardware. I never figured out why, just dealt with it. That was about 5 years ago so I forgot the specifics. Now I just know I need to experiment sometimes to get the right one and I also know that if I switch drivers, the IP address will get changed for me, so I select and copy it, change drivers, then paste it back in.