E6400 BSOD and OVERHEATING

Hello all!

I have been a fan of Dell for most of my life, and this is my first post.  I am a technician for a public school system, and we recently purchased 9 shiny, brand new Latitude E6400s to be used by the teachers.  Everything ran beauituflly for about a month or so.  Currently five of the nine are experiencing the EXACT same symptoms as described below:  

(1) When the laptop is connected to a projector (Epson Powerlite 83C) the laptop does not detect the projector after pressing fn+f8 multiple times.  After a few minutes, the laptop freezes, then blue-screens

(2) When the laptop reboots, the BIOS errors out with the message shown below:

(3) After the laptop has been shut down for a few minutes and cooled off, the laptop boots into Windows XP as if nothing ever happened!!!!

(4) I requested a Dell support technician to come look at them, but he can find nothing wrong with the laptops

(5) I have run EVERY single update available- BIOS (A12), NVIDIA drivers, chipset, etc - nothing has made a difference with it!!!

(6)  I have run every single test on the DELL DIAGNOSTICS CD, all come back 100% passed!!!

(7) Does anyone have ANY ideas what else I should try??? I'm at my wit's end!!  I suspect it to be a heat issue, but I cannot reproduce this issue as it is EXTREMELY random.  Unfortunately, this issue happens at EXTREMELY inopportune times for my teachers.

Thank you for any insight!