Dave,
I performed a ground check using a different aircraft,after the last fllight on 4 /14 when I encoutered the problem. The flight logged correctly and since I did the ground check, that bb log was replaced. I looked at the replacement log, being it was a ground check did not show much but what I saw was normal!
Now a while ago,today, I performed a check of the different voice systems i.e. Crew sets, Check list voice checks, and all was right this time.
Now during the ill flight when FS was unpaused, the message appeared that FDC was active.
My conclusion is that FDC had a parial incomplete loading.
I will try it again and see what happens.
Thanks for the response.
Cheers
Alex