what were you doing when the files were corrupted? Usually, if you move the file location, or if you have selected the option to auto sort music in media library, you will get a corrupt file, the problem is the program no longer knows where to find the item, the solution is to organize first, then create playlists, and coppy music
check your options by selecting the tools menu, select options, click on the media library tab, then look to see if you have selected update music files, and if so you may want to change your settings to add instead of overwrite, and make sure you have not selected rename or rearrange. I like to use these options, but you have to organize first, then make playlists and coppy, media player will rearrange automatically, but not untill you close all windows that are using the file (player, my music, ect.) remember the program needs to know where to find the file.