Here is the manual for this player and it is explained in the begining the disk types and formats that are supported by the player ..If you pay attention this unit will work well with all original dvd , dvd-Rs ..and vcd ..and also audio cd (cd track ) but the mp3 are only played in ISO 9660 format ...
So if the cd is burned into a computer and it has a different format ..it will not be seen by the player ..
I will link the manual ..and also the explain of the iso 9660 format ..
http://www.smarthome.com/manuals/972448w.pdfhttp://en.wikipedia.org/wiki/ISO_9660The idea is to choose this format when you want to make a mp3 cd and be playable into this player ..If the files are wma ..or mp4 or the disk formatting is not the one specified the player will show you the unsupported format error on the display ..
My advice ,if you have a cd with some files you need and it is not seen ..., is to copy them on the computer's HDD ..and than use an audio converter to convert all files to mp3 ...and than use a burning software to burn them in iso9660 format on a cd ..Place them without folder and be sure you chosen the format in case..or ..if you think you can not manage ..burn the files as audio cd ..playable in most cd players ...To do that choose to burn audio cd using windows media player ..add files in a play-list ..(no more than 15 up to 18 files) and than choose to burn them on cd (in windows media player ) They will be converted in tracks first ..and the size will be determined by the time (80 min ) and there will be no more than 18 tracks on a disk ..This way you will be sure it will play on this unit ..