I upgraded my Xenon from freeBoot 0.32/9199 to the fbBuild kinect/12611 dash (not "early," all files recent and from "the usual place," never connected to LIVE, etc.) and everything seems to work fine except for playing videos. I am using the same hard drive with my "Yaris swapped" optional media update on it, and, attempting to play videos from a usb hard drive, both of which worked fine (changed nothing) before flashing. Now, when attempting to play a video, after hitting play, the screen goes black and controller is unresponsive, though you can hear the audio portion of the video playing. You can't stop it from playing, but if you play a short enough one and wait, once it ends, screen and control return to normal.
I've rebuilt/reflashed my freeboot image a few times, always using freshly extracted original to this console files, flash dump verifies every time, redid the yaris swap on a fresh copy of my own backed up/untouched media update (same outcome) but can't think of anything else to try.
If this is something obvious please let me know, but I couldn't find anything similar here, only this on x/s: