Most of these cheap divx players are completely and utterly crap. They'll play next to nothing and more often than not they'll pack up after a few months or the roms are often dodgy. You get for what you pay for and every now and again we get something rather quite special that will play everything.
I remember buying a warfdale from nettos and it played a couple of times before the rom packed up and even when it was working the backups I made of my movies were stuttering along because of the crappy roms these cheap media players have. I eventually went back to using my Kiss500 player before giving that away.
I never play my original blu-rays, dvds and will always make backups of all my stuff and play the backups I make then store them onto my hardrive and play them on my
Western Digital WD TV HD Media Player (after a firmware update) will play everything and nothing ever touches a bluray disc, dvd disc, or any type of disc.