> Ah, right, that's interesting.  So the current millisecond clock value
> should be stored with the offset, and if the clock ever drops below
> that value, that's a signal that you need to recalibrate.

So how would you recalibrate?  You know the value of the
millisecondClock when first starting the image, but if it rolls over,
what was the max value of the millisecondClock before it rolled over? 
Is this defined specifically anywhere other than as some power of 2? 
Is it a signed 4-byte integer?  Or is this a platform-specific "pipe
sticking up through the floor" problem?

John

-- 
Three failures denote uncommon strength. A weakling has not enough
grit to fail thrice. -- Minna Thomas Antrim