This is an old problem. If you can't find a fix you can do it yourself.
I haven't got the F-16 installed right now so this is from memory. Try it on one variation of the F-16 first.
Find Inglass.bmp in the F-16 Texture folder. Open it in DXTBmp. Click Alpha/Invert Alpha. Click File/Save As/Extended Bitmap. Save it in DXT3 format. Overwrite the existing file when prompted.
Check it out in FSX. If it worked you can paste a copy of the edited file into all other F-16 Texture folders.
Download the latest version of DXTBmp here -->
http://www.mnwright.btinternet.co.uk/programs/dxtbmp.htm