If you are unable to play some of your iTunes tracks in itDJ and receive an error about a DRM restriction, it might be caused by Mac OS X not giving itDJ access to your files (an issue fairly unique to Mac App Store apps), so please try these steps:
1.) Click on the file name to the left of the round, silver Record button near the top, center of itDJ.
2.) In the File name/Location popup that appears, click on Change...
3.) Choose the folder that contains your iTunes music. Usually, it's going to be in your Music/iTunes folder, but in case your files are in more than one location, it's recommended to choose your entire User folder (the one with the house icon in the left panel of Finder).
4.) Once you click Choose for that folder, itDJ should then be able to access all of your music.
If you still are receiving the error for non-DRM tracks, please contact our support team by clicking on Email Us on the right side of this page.