DOUBLE DIN QUESTION!! HELP ANYONE

[B18lshatch]

I just bought a nice Power Acoustik Double Din. Here is a quick scenario. It supports these file types,MP3,MP4,DVD,DVD-RW,CD,CD-R,CD-RW and DivX. It also has a SD slot in the front of it. I have a SD card and i have put music videos on it and when i put the card in the cd player. it says SD Error. all the videos on the SD card are MP4. Has anyone had any similar problem to this. or may just know how to fix it??? Thank You for the help. Other wise this thing is awesome.
Model : PTID 7250nr

[khaxnguyen]

SD card could mean that your SD isnt function as it's suppose to--higher chances of failure if you've bought a fake one. save the files on your computer and reformat the SD card(using the deck if possible). try using different converting programs to convert to mp4 again? i also see "divx", try converting to .avi files. maybe the deck is bad? and lastly, read its manual.