Hello FuturePilot,

are you using the Nvidia plugin, DXTbmp or Convimx ... ?
if it's the Nvidia plugin and you are saving your file, in the opening nVidia window you have to select flip image (I think it's in the lh lwr corner - check it).
In DXTBmp its: Image - Flip image (for DXT1 no Alpha) or - Flip image and Alpha (DXT5 f.expl.)
In Convimx you have a tick box in the middle of the window which has to be set to flip the image. (this little sw allows batch conversions which can be interestening to save time)
And then there is at least the method with the image converter that comes with the FSX SDK. Check out the other Post where it is explained better than I can do.
brgds, Lex