Help - E6440 BSOD BCcode 9f

A few months back my company bought a few Latitude E6440 units (about 7-9 of them) and every single one of the has been getting the same exact BSOD, BCcode 9f.

It has been a nightmare trying to get these things fixed. I'm simply looking for any suggestions anyone may have to help resolve this issue. I've been to countless forums and have had to deal with literally dozens of Dell Techs. On multiple occasions, We've had onsite Dell Technicians come to replace the Motherboards and daughter boards for each of these units without any success. We've taken one of the sticks of ram out at a time to see if the issue would still persist(it did for each stick), we've also had to swap the HD itself on a few occasions(no luck).

I've ran Windows Memory Diagnostics tool(thorough) with multiple scans without any issues being found. I've ran chkdsk, sfc /scannow, Ran the Dell Diagnostic tools(before and after upgrading to the latest BIOS version, A07) . I've updated each Driver that I could find available on the Dell website and using my Driver Pack Solutions v14.7(on a separate E6440 having the same issue). I've gone back to Dell's factory image on the machine itself and used a Dell Win7 Pro x64 disk to reformat the units and repeated everything else I've stated thus far after the reformat on each unit. Still the BCcode of 9f plagues me.

I'm sure I've skipped a couple other things I've done along the way. Any help would be greatly appreciated at this point. I just don't know what else I can do to resolve this issue. I've dealt with at least a dozen Dell Technicians at this point and even an engineer without any success. 
I truly regret purchasing these units...

(I'd upload a couple dmp files, but it appears the forums won't let you attach those kind of file extensions, funny for a forum of this nature)

Any advice would be greatly appreciated at this point.