Songs added to Media Monkey keep disappearing

[Algood001]

I have added songs to Mediamonkey from my desktop. One album I added keeps disappearing from Mediamonkey in the next day or so. The album is in mp3 format and it is still on my computer, but it keeps disappearing from Mediamonkey. The Artist folder is there, all the songs are listed there, BUT, when I select one to play, Mediamonkey quickly goes through the album list, but plays none. This is one of my favorite albums so if anyone can help, I would appreciat it.

Thank you, Al