[PROBLEM] System freezes after a while

[rph-r]

Ok, interesting, so maybe I'm not alone...

I did some short tests:
-I disabled sound devices (set to none): there is obviously no sound, and the problem remains the same
-I re-enabled device, disabled local display (local UI display: off): touchscreen starts to prompt, and after three hours the remote web interface and SSH still works perfectly!

What do you think?