I was getting some spikes and blue rectangles but they only lasted half a second and were intermittent. But I called Alienware tech support jic. The end result was them sending a certified Dell tech to my house to install a new video card. Before the tech left we fired up FSX and when changing views with the 'A' key, I briefly got a tan screen. But then it seemed to settle down and other than a slight drop in frame rate, was fine. A couple of hours later my Saitek was returned after repair so I hooked it up to check. I started getting the blue/tan/black screens everytime I changed views, as well as lock ups. And when it did work, stutters with very low frame rates. Suspecting the Saitek might not be fixed, I disconnected and tried using just the keyboard. Same result. It has since stabilized slightly allowing some extended flight, but the problems still show up on occasion. There were no changes in any settings or any additions when it was working fine shortly before the tech arrived and since he left. It is exactly the same in the original install and the copy/duplicate install. And I have to run FSX in window mode because full screen frame rate/stutters will not allow flight. Before, I always ran in full screen with frame rates around 30.

I also sometimes get an error message saying the display driver has stopped responding and has recovered, though the lock up continues. Sometimes it will stabilize and allow flight, sometimes not. I also found two identical entries for the video card under Display adapters in Device Manager, identical except one is on PCI buss 10, the other on PCI buss 11. I have no idea which one was the original. I tried disabling one, then the other and both times system reverted to default. It would seem to me that if one was the original which is no longer connected, disabling it should have little or no affect but this was not the case. Any help appreciated.

No, did not think of that, but will try it. Thanks.

My card is an ATI Radeon HD 5970. The driver for it, is an older driver for the 5870. I don't think an older driver is available for this card.

I just spent about two hours on the phone and connected to Alienware tech support. He downloaded and installed a new driver. It appeared the issue was fixed in FSX. But then he had me load FS9 and the tan and black screens showed up and the sim locked up. He said I had two options.
1. Install another new card. (I don't think there is anything wrong with the card.)
2. Re-install windows. (I really do not want to do that.)
He said with a re-install of windows we would be able to tell whether the problem was hardware related or software related.
I think it is all related to computer, card, and sim settings. But then I don't know much. At this point I am going to back up all my files to my outboard drive and test FSX further. I am not going to get in a hurry with my decision concerning the re-install.
Thanks for the suggestions. 

Now Paul, don't be petty. 
You are right though, upwards is not always better, especially if your engine quits. 
However, I did quite a bit of research about my video card and found some very interesting things. One of which, is that there is an 'enhancer' program for ATI. I have not tried it yet, but I plan to. Anyway, after reading all the stuff I found, I made some changes to settings in both FSX and ATI Catalyst Control Center. I was able to complete two flights without any difficulties other than some minor jaggies. No lock ups, no tan or black screens. I ran in window mode, but resized to almost full screen. I took a bunch of shots and hope they are good enough to post later. The first was KBLU (Blue Canyon-Nyack) to KTRK (Truckee-Tahoe) and the second CL01 (Eagle Field) to KSCK (Stockton Metro), by the scenic route, not as the crow flies. The second  took me a little over an hour. I started to land at Lodi, but did not want the song to come true so I diverted to Stockton. 
Hope to have most of my problems resolved soon. Thanks for all the help guys. And don't worry Paul, I'll eventually post some more FS9 shots. 

I am still convinced it is a matter of settings. I just found a link in the Hardware section, 'ATI 5850 settings for FSX' thread, that I think might solve all my problems. I'm off to do some reading.

No, I have not, but the factory may have. I don't know if it means overclocked, but Catalyst Control Center shows Overdrive enabled, clock set at 725MHz (max is 1000), Memory Clock set at 1000MHz, (max 1500). Current Values are GPU clock 157MHz, Memory Clock 300MHz, temp 51C, activity 0%, & fan speed 26%. Of course it is not doing much at the moment. 51 to 70C is normal. but everything is grayed out in the overdrive section, there are no changes I can make in CCC. Have not downloaded Tray Tools yet and do not intend to oc card unless absolutely necessary.

875 watt. The ATI 5970 HD minimum requirement is 650 watt for a single card, 850 watt with dual cards via Crossfire. I think the 875 watt is enough for my single card.