Ah hello there so you having that problem with the importing audio in flash problems? Well I have the ANSWER!
The Solution:
In the case of WAV files, it wants PCM wave files... so if your file is in another format, you'll need to convert it. That simply consists of going into your audio editor of choice, loading the wave file, and saving it as another file with different encoding options.
With MP3 files... well, Flash doesn't like them with bitrates over 160kbps. But you can make it play nice by installing Quicktime. Flash will talk to Quicktime behind the scenes and use it to import your MP3's without the dreaded "One or more files were not imported..." crap.
sooo this is where you should go.
DOWNLOAD THE AUDIO CONVERTER TO CONVERT MP3 to Wav files.
Go to this link and download it > http://www.nch.com.au/switch/
The download is free. Go ahead and convert your mp3 to wav files, then save the NEW WAV files in a special folder and then import those WAV files into flash. Try that! workd for me! :)