iTunes Match problems: Some mp3s have location error status after I downloaded them from iTunes Match.

I have a huge music library and I decided to upload some of it to iTunes Match. My iphone is small and I was constantly shuffling media and I wanted the high quality sound files to download back onto my computer. I went through this laborious task and now the first song on my albums has the status of missing location. It is not on my iMac and it won't download it or find it in iTunes match.

I can find it on my phone but not from my home computer. Has anyone else had this problem? Any ideas on how to solve it?

Thanks,

Tim