I do have exactly the same problem.
i210-T1 Adapter with manufacturing date 05/2014 works fine on every system listed below.
i210-T1 Adapter with manufacturing date 08/2014 works not. The error is exactly the same as described by Hitman4HireTN. I also tried to disable the onboard adapter. Doesn't work either.
Error occurs on:
Dell Precision 390 + T3400 + T3500
Dell OptiPlex 780+790
Have there been any possible solutions since now?
BR
Thomas