Yes, i've looked at every Rk27xx firmware on
http://www.qqmp4.net/
I found you can pretty much mix around everything and the player will still boot up, but you can't get much in the way of extra functionality, all I have able to do so far was move the text on the player by swapping the CWIDTH16.BIN with the CWIDTH24.BIN renamed to CWIDTH16.BIN
The one to crack is BASE.RKW for extra functionality, problem is if you play with that the slightest, then the player doesn't boot up, there is some checking going on and it takes place within BASE.RKW itself.
I've swopped around REGISTER.DAT and the codecs, no problems, if you swap BMP0.BIN around the player will still boot up, but of course all the pictures are messed up and in the wrong place :wink: