Danny, because your computer recognised it as Rockchip, then perhaps I was wrong!!
ops: Sorry about that!! Anyway, in my experience with Rockchip players, they need the movie to be in exactly the right format, with not even one pixel extra on the "X x Y" settings for the movie size. If your demo movie is 176x220, then perhaps try and encode a movie at that size. I cannot remember if Aviconverter gives that size as an option, but I have found Xilisofts DVD to MP4 converter to work perfectly. It's quite pricey, but you can download a demo version which should let you test things out, and I know you'll be able to type "176x220" in the Video Size option.
Please see my post above for details on using their software.
Cheers. iixorbiusii