Build Nightly.2015Mar02.650D104. Pressing Zoom-In button (loupe+) during MLV or RAW recording will freeze the cam. Most buttons will not work. Switching "Power" button to OFF will cause shutter to close and mirror dropping. Opening battery compartment door won't do anything. Have to remove battery to shutdown cam. Have no own logs. User blade delivered his, confirmed the bug is in his system, too.
EDIT: Haven't tested other builds, yet. 2nd EDIT: ML settings on default -> Activate MLV_REC.mo or RAW_REC.mo -> Restart cam -> Activate RAW or MLV recording -> Start video recording and let it run for a few seconds -> Press Zoom-In: Freeze