Latitude E6440 imaging issue

I'm guessing there may just be something with the laptops themselves. I can run a E6440 through MDT and it will finish fine. Then, I reclone it a bit later, and it hangs at installing devices. It will get to about 65% and take forever to finish (2 hours)...sometimes even blowing up the unattend (Windows cannot parse....). Then, I can reclone the same machine and it goes right through. I've not seen this with other models, just the 6440. Any ideas?