Dell e6540 NIC issues

We buy dell laptops for all our users at work and we never had any issues with the 6520s or 30s.  With the 6540s, however, the NIC just dies inexplicably.  This has been a problem on a multitude of these models, not just one or two.  So the problem is as follows, boot up the laptop, everything works fine.  Use it, go on the web, etc, everything works fine.  After a while though, the NIC will just die.  Wifi, RJ45, no difference.  Nothing comes up and the laptop must be restarted.  No ipconfig /release or renew will work, disabling the adapter and re enabling it doesn't work either.

One particular NIC killer for this laptop is RDP.  If I am at home and I RDP into my laptop at work (it is on a docking station 24/7 just about), it will work but the next day when I get to work my NIC is dead.  Guaranteed.

So if I have to work on an issue from home (I'm in IT), I can solve an issue but if I get another call and have to RDP, I will have to RDP to another computer because mine is now dead and I can't restart it either because I'm remote (go figure).  So I will remote to a co-workers computer, then his is dead the next morning too, requiring a restart.

Another coworker of mine has a 6530 though, and he has no issues at all.  We have tried to get Dell support to fix this issue to no avail.  We have tried updating the driver, etc, and that doesn't work either.

Just need a fix.