Another Calorie Coach glitch

CalCoach had been showing a 'thumbs up' for (I think) all of my first 29 entries (at least, as soon as it had sufficient data). Yesterday I posted my 30th entry - another loss (4.4 lbs) but CalCoach got upset and gave me the thumbs down, which was still there this morning (so it's not a "tick over at midnight" error). I have just made an additional (31st) entry, giving the same weight as yesterday, and the thumb is up again and a whole month has been lopped off the target date.

Just for fun, I went back and edited my 31st entry (to show a 1 lb gain from yesterday) - still thumbs up.

Odd, very odd.

Is the 29th-30th-31st entry significant? (NB. "last 30 entries" function). Or does the error lie elsewhere?