EDIT : Please ignore this information. (see my follow up report further down this thread).
Have been experiencing a strange problem of late with severe corruption and skipping on the occasional recording whilst the majority have been perfectly O.K.
I only use the T2 for recording and always view live channels directly from my Samsung TV, as it has a built-in Freeview HD tuner. I couldn't see any pattern to it till I finally realised that the corruption was only happening when there were two concurrent recordings scheduled. One recording was good, but the other suffered from the corruption.
Once the penny had dropped it was an easy matter to prove by simply starting an instant recording then changing to another channel, forcing the box to use tuner 2. And yes, the live picture using tuner 2 was badly corrupted so I suspected that I had a physical problem with tuner 2.
Opened up the box and examined the board for any obvious signs but it all looked O.K. so put it back together again. Tried an autoscan and this didn't help so then did a manual scan on each mux.
Still no joy so with nothing to lose I went for a factory reset. Stopped the subsequent autoscan without saving and did a manual scan once again. Would you believe it, the corruption on tuner 2 was gone. Just to confirm things I did another autoscan and the corruption was back on tuner 2 once again. Another manual scan didn't fix it so it was back to the factory reset and manual scan only, to get the two tuners working correctly.
I really don't understand how one tuner can work perfectly whilst the other fails when both are supposedly using the exact same autoscan data. I was almost at the point of replacing the box so I hope this information might help others who encounter a similar situation.