Posted for Walter Atkinson <walter@advancedpilot.com>:

 Those findings are consistent with pre-ignition... most probably from a bad
spark plug.
 
 Why a bad spark plug?  Possibly detonation induced damage on the ceramic.
 Reasons for the detonation can be many.  Superchargers can be a part of that
problem if all factors are not considered and accounted for.
 
 Walter