POST and BlueScreen issue related to multiple video cards

Hi, I have just built a Windows 7 PC (Professional x64) and have only loaded in minimal applications and the primary required windows updates. Before this however I would get an odd start-up hang during the POST cycle. This is likely because I use 3 video cards 4 monitors, and an overhead projector (all for an advanced flight sim which can be seen on my website!

PCIe-SLOT 1 - BFG GTS-250 --- Powers two 20" LCDs
PCIe-SLOT 2 - BFG GTS-250 --- Powers an overhead projector
PCIe-SLOT 3 - BFG 7900 gtx --- Powers a 20" LCD and a smaller 15" LCD

Q9550 / EVGA 790i DIGITAL PWM Motherboard

During POST the screens sometimes comes up in my primary 20" monitor (PCIe SLOT 1 card) just as it always should while other times when starting the PC the POST inversly starts up on the PCIe SLOT 3 card / 20" monitor. When starting from the PCEe slot 3 / card 3 the POST cycle hangs halfway through the POST giving an error stating that "Video Card 3 is in PCIe slot 2". and that I must "place it in slot 2 for SLI operation". (I don't want SLI !!)

From this point I cannot access the BIOS via ALT or DELETE and simply have to hit the RESET button and once done it will often (but not always) correctly POST in my PCIe SLOT 1 Card / primary monitor and start up just fine with no other issues.

Its very much "tit for tat" --I restart once I'll get the error, restart again it will sniff out card 1 / slot one properly, then restart again and I'll get the 3rd card POST with the #3 in #2 error and so on. error, no error, error, no error, etc.

This is extremely annoying as I know I have set everything else up properly and have correctly loaded the newest NVIDIA drivers (197.45) Just as a precaution this is my second Windows 7 reformat of this new PC with new harddrive and I have also reflashed the BIOS to latese rev. and have lastest rev. motherboard drivers. Everything is up to date as it should be and when up and POSTING from the correct PCI-e SLOT 1 / CARD 1 the PC starts up perfect and runs perfect.

Its only when the computer has to be restarted for any reason (such as for updates) will it again hang up on the PCIe SLOT 3 "card 3 in Slot 2" issue. Again a quick RESET usually solves the issue but sometimes I may have to reset twice.

Do I need to ditch the older 7900 gtx card for a newer 200 series? Is this issue that simple? I will point out that the drivers set (197.45) are the same. I have scoured the BIOS thinking I am missing a setting but did not see anthing related to making the motherboard always post from Slot 1. I thought motherboards ere supposed to always post from Slot 1 anyway!

Now the last time this happened it reset to the card 3 position AGAIN and did so twice before POST to the correct card 1 position. Once back on the desktop there was this BSOD error message; (which may be totally unrelated to the POST issue) as I attempted to set up a sleep power profile with a wake timer and wanted my virus scan to run 5 minutes after the wake-up and it didn't work. -- At some point the BSOD happened, the computer restarted, but hanged during the Card 3 POST and hence once back to desktop I found this error mesage below:

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.48
Locale ID: 1033
Additional information about the problem:
BCCode: 1000007e
BCP1: FFFFFFFFC0000005
BCP2: FFFFF880103BD708
BCP3: FFFFF880031BCB98
BCP4: FFFFF880031BC400
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1
Files that help describe the problem:
C:\Windows\Minidump\052510-21902-01.dmp
C:\Users\Sauron\AppData\Local\Temp\WER-43555-0.sysdata.xml
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C:\Windows\system32\en-US\erofflps.txt

---P.S.--- I checked the mini-dump folder and this is the only error;
the 052510-21902-01.dmp

Thanks for any help or advice you folks can give!