Compatibility issues can come from a couple different places when dealing with digital media. I looked up your device here http://reviews.cnet.com/car-audio/alpine-ida-x100-digital/4507-3425_7-32790566.html for your digital specifics. I am under the assumption that you are trying to play MP3 files. Your Alpine reads ID3 tags and this could be where a lot of your issues are coming from and some could possibly come from the file name of your MP3's. Most car audio decks are not equipped to handle characters that people put in the MP3 names or ID3 tags. If you notice how the working MP3's are titled on your Alpine's display it usually reads something like "song - artist". If there are characters like "~ # ^ $" or something to that effect, your Alpine might not be able to read that. If the MP3 name is already written like "song - artist" then the problem could be in the ID3 tags and they could have unreadable characters in there which are not visible to you without a ID3 tag editor. In this case, download a free ID3 editor, trying clearing it out or modifying it to a simpler format, edit your file names as needed and try that out.