Very high counts in random channels of the 1-DC. This would occur even when the DC power was off. The spectrum would look good in cloud; except for some random high counts in some channels. The problem seem to started with the switch to the new M300 data system and last upto and including the Sikorsky ferry flight to Alaska (September 13, 2005).
Bad 1D256 card in the M300
The 1D-C was sent in for cleaning and optical alginment.
Talked with SEA and figured out the it was most likely the 1D256 card. SEA sent a new card to Fairbanks,Alaska. The new card was installed on September 15, 2005. This seems to have solved the problem.