I've got a problem with my Mutant 2400 receiver. When I play mp4 files, after two minutes the audio is muted, the video is stuttering and after a few second the video freezes. On my old Dreambox 8000 playing the same mp4 files is no problem. Anyone an idea what is wrong?

My configuration:
Hardware: hd2400 (2-2)
CPU: BCM7425B2 1305 MHz (2 cores)
Image: OpenPLi 4
Kernal version: 4.0.1