Bossie has analysed this in depth - see all his posts.
In principal it is but the real issue is the processor does not have the processing power to handle all the interupts at times. This is an old problem Id'd when the very first PACE 4T decoder came out. MC has workarounds for some of the issues but in the end, the problem remains.
There was a claim that later versions of the PACE 4T and the UEC 4T and the 2P all had better processors.
Having opened the 4T decoders I have, and had a look, all I can say is that the processor chipset in my decoders are all obsolete legacy devices already.
"Bandwidth, or more accurate, Data Rate, is a commodity, not a value added service"
Easyview, UEC 4T HD PVR, SD PVR, XV
Spare decoders: SD PVR, PACE HD PVR 4T, DSD 660