@Letourn
Sorry I had not replied to your email on this issue - I had not been working on the F-35 in the past few weeks, so I forgot to reply to your message.
The UVW coordinates appear to be mirrored - there is no way you can fix it - it has to be done in the 3D model. I'll do that in the next update - which should be released in few weeks.
@ All
Just my two cents, but I find really convenient using the Imagetool with a "command line shortcut" (i.e. a shortcut which calls Imagetool with proper options). It is really easy, as you simply drag and drop your files on the shortcut icon and it does preserve texture size.
Sorry I cannot provide an example right now, but I am away from my FSX computer...