Another theory: The stuttering seems to be related to time - fine for an hour or so then it starts. I have tried RC3 (couldn't get it to work) 1.1 alpha - no joy, so reinstalled 1.0.2 and things worked fine on default settings then stuttering started. So how about heat - i have an unfanned (silent) en9600gt card. The HVR2200 is also a PCIe card and is no more than 3-4mm away from the graphic card. On testing the 9600 has so far got up 63 deg C - could heat buildup slowly begin to disrupt the TV card? Heat sink is next to back of HVR2200. I'm testing recording TV without streaming live at the same time - no detail on that yet. Live streaming took GC temp up from high 40s to 60s.
Heat indeed is pretty valid source for tuner related signal errors. You could try to remove the case as soon as the stuttering appears, maybe that lowers the temperature enough that the tuner will work again correctly.
Also when the stuttering occurs please check contents of TsReader & TsWriter logs. They should be showing up discontinuity errors when tuner doesn't work properly (dropped / missing packets, corrupted stream etc.).
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