I did update my jtag to 14699 and test one of my old hdds and non of the old games on the hdd works, only some kinect games and some new games.. i did use Xebuild.
it started in fbBuild_0.33 "old" games dont work and the Error is "The game couldn't start. Try downloading the game again. For more help visit www.xbox.com/support
its a falcon with smc aud_clap