WDS 2008 R2 and a Lenovo t450 NIC driver

I ran across this same issue with a T450 recently and was able to resolve. After updating the Deployment Share within MDT, I had to replace the Boot Image in WDS with the newly updated .wim file. It seems the previous admin that set up our system had our boot images named differently and located in a different directory, hoping you have solved since your post but wanted to throw my $0.02 in.