Magical Photoscenery Drift Sudden Appearance...

Somehow while I've been working on a photoscenery project, when I had had everything lined up with WGS84 data, suddenly it has jolted in the sim and is now off in the sim...I went to a reference lat/lon to find the image has somehow shifted even though the values I used were correct and were tested and confirmed accurate in the sim...I'm left scratching my head... I have since gone back and double checked old versions I made which I know lined up and suddenly they're all off from where they once were too...I had all my phototiles pefectly aligned in the sim, and it was verified against terraserver images and lat/lons... The same BGL's and BMPs that I was able to confirm as being correct in previous versions are now not correct when I've placed them back in the sim...In fact I now have a nice seam that has opened up in the middle of the airport I have beem using as a crucial reference point...I'm going back to square one and regenerating the code by hand to see if I can't get this all straightened out, but I am at a total loss as to how one BGL/BMP rendering can be perfect one moment in the sim and then later on when it's re-installed it is suddenly off...Could I have found a bug in the FS engine? Or could it be one of the dll's I used for using some of the LOD tools?What's weird was that I rendered a version last night that worked, and then a few hours later I've run into the problem that seems to have magically appeared...Left scratching my head...