i got serious problem with my blender i cannot solve. when im trying to send my models to someone else, half of my model faces are missing. Kaiser says that normals are f****d and looks like he is right, but i got no clue what is wrong

(what is funny, even in texture mode in blender these faces are missing, but when i open models with 3dwings everything is ok :D)

- this is view which shows normals, i hope you can see that many faces (like under cannon) dont have... well these blue something.
and i already used recalculate outside and remove doubles (Kaiser suggested its problem with my modeling metod, but i just start circle, extrude edges, merge vertices... and well thats all i use most of the time)
