Why does iMovie trailer skipping frames?

[Micro-Dona]

I have created a trailer by using iMovie installed on iPad 2 of mine. I was ready with all the scenes and when I pressed on play button the trailer played without having any issue. however when I was closing the exit menu and played the trailer again then it asked me OPTIMIZE movie. I was looking to export trailer to the camera roll. Once I have done optimize I noticed that the trailer which I have created loose several quick scene. So there was no purpose left to create the trailer. Can you tell me what is wrong happening with me? Can you tell me why it trailer was playing fine when it was not Optimized? Any help on this particular matter will be highly appreciated Thanks a lot in advance.

[dkbose]

Previously I was wondering that optimize supposed to take lots of processing power and that could be the root cause of frame drop. However after doing lots of research work I concluded that was no dropping happening because of optimize. If you are not supposed to render or optimize then iMovie could skip frames when it is being played on your iPad. According to me it does not seems to destructive at all as devices is not able to stream that data at faster speed. Let me know whether you have exported the camera roll. If you have not done the same then I am saying that you should simply export the camera roll and view the video through Photo app itself. This will let you know about the final quality of the video trailer which you have created. If something is missing then I am sure that it was happening just because of bug issue and it should be fixed by Apple.