Missing frames?

When im in camera view in toon boom i see my keyframes with the drawings in them but after i export it as a .swf everything else is there but the drawings in certain keyframes are gone. What should i do? Help would be greatly appreciated ;D

Is it always the same frames that are missing? Or is it random from export to export?

Are the drawings exposed on those frames?

If you continue to have problems exporting your file, then probably the best thing to do in this case is to email your scene to techsupport@toonboom.com, so that they can take a look at the scene and determine what the problem is