This shows that these dropouts are a fault of DVB Dream and not the driver or my hardware.
Looks like there are less errors on faster systems, but 850 MHz should be enough for recording and Recording errorless should have a higher priority than decoding.
It would be a shame keeping or sharing broken records

It seems the TS handling is included in the callback function. Little delays in hard disk access may block the callback function of being invoked by the driver.
I suggest the callback function should only write to a large enough buffer and then leaves immediately to be ready for the next packet. Packet processing should be included into another thread.