Perhaps I just had bad luck, but I had two cards fail from this malady over the last two years...
I reflashed them and have a good working one now, but took the good advice from folks here, and started shutting it down manually each and every time now - never had another issue.
Could be the newer cards are now "fixed" or it could be I just had a couple of bad cards, but this did happened to me (and I have plenty of old posts to prove it). In fact, before this thread started, I asked HOW we could tell the STRATUX was shutting down using the softkey to shut it down on the Ifly MENU page.
Believe me, when it happens to you in flight, it is very frustrating.
The way it was explained to me was akin to how you shut a computer down in your home...would you just pull the power or would you turn it off first?
Perhaps this does not matter or is a bad analogy, but it made sense to me at the time and still does.
Your own results may vary!
Thanks for asking this again and big thanks for going right to the designer for a definative response.
Mike N714AJ