Replaced a T1020 with a 2100 after it looked like it got a power supply problem after 18mths use.

First issue the HDD format appears different so no easy way to seamlessly carry old content across (but the T1020 is accessible from a Win 10 computer so the videos are recoverable but to get the HDD to be recognised by the 2100 it needed to be reformatted and the new 2100 format doesn't seem to be recognised by Win).

First sound problem was the volume fading intermittently (HDMI to Samsung LA32B60).  Solved by turning off Auto Volume on the TV. 

However when replaying recorded programmes if I fast forward and then start to replay the audio is out of synch.  It gets fixed by completely stopping the replay and then resuming.  Would seem to be a STB/HDD issue.

Any thoughts?  HDD is a 1T Western Digital.