I too initially thought that it was a video memory issue but through my own testing, as well as some done by the company that built my rig, it has been determined that this is not the case. I can fly to any airport in the world without issue -- the issues I reported only happen when I come in the vicinity of the FSDT airports.
It IS a video memory problem or a driver problem or a FSX.CFG tweaks problem.
Fact it only happen close to an FSDT airport doesn't mean it's not a video problem you already had. It simply means that, the other sceneries/products you have, don't use the video card as fully as our sceneries do, so you don't have the chance to notice a problem with your card/driver/settings on other sceneries, because they don't use the features that have bugs.
After the video memory testing was complete
Memory corruption doesn't have anything to do with video memory being defective so, if with this you mean you used some kind of diagnostic tool to check if the video card memory was fine, it's not what I meant.
VRAM corruption it's an entirely software issues, caused by video drivers bugs, video settings wrong, FSX tweaks that shouldn't be applied, entries in the registry related to old video driver versions or simply too much memory taken by memory hungry add-ons like airplanes, or ANY combination of this.
Can you offer any possible solutions or tasks for me to attempt in an effort to rectify these issues and return my sim experience to normal?
I already listed all the solutions. Try them ALL. The only additional step you can try, is to use a driver cleaner before reinstalling the video drivers, like this one:
http://www.guru3d.com/content-page/guru3d-driver-sweeper.html