Hey I have the same problem. Tried all the codecs and the drop frame box, etc. but there is this program Voltaic HD which I read about on a macrumor forum on this topic that will convert the video but it takes up to 12 times as long which is no good. high quality and retains the 5.1 channel sound though. another downside is that its $30. lame. i hope apple releases some more codecs/is there a way to put other, working codecs into fcp? how come imovie will work and not fcp? is there a way to copy the settings from imovie to fcp?