imoviwe can't import downloads
 

I just upgraded to OS X and anything I download now can't be imported into imovie. Stuff I downloaded before upgrading can still be imported. The files are all saved as mp3 audio files ( same as before) the only difference is that the new downloads have the ( i Tunes icon) and the old ones have (quicktime icon). I even opened them with quicktime and did a save as... but nothing. Is there something I'm missing here?