distorted audio when importing

I have upgraded to the latest version of iMovie (as of today, 10.1.11). I can import video just fine. Looks great. However, I have real problems importing audio into iMovie itself, and then into the timeline. I ripped the audio from another movie (nothing copyrighted) and it plays just fine in VLC and iTunes. Checked it yesterday. However, when I try to import it into iMovie, delete the old audio *that came with the original video, and then try to add the audio I have ripped and save, it sounds robotic and horrible, and nothing like what I ripped at all. I have tried changing the format to a more iMovie compatible one, mp3, mp4 audio, AAC (both low profile and main profile) and m4a, and upping the bitrate to 256 rather than 192. I have turned on and turned off Variable Bit rate encoding thinking that would make a different and fix the problem. It did not. So yes, I can't do this at all. I am stuck and stumped as to why this is happening and what I can do to fix it, which appears to be nothing. Please, any suggestions welcome. The Old version of iMovie worked fine for both video and audio. No problems at all importing and working with either one or both, but this version......