Hi there Helen & Jason,
thanks for your replies.

Helen: no cached updates anywhere in my app, but the advice is good
to know, thank you.

Jason: I did as you suggested (I'm just now slowly getting used to
stepping through the IBO code. Doing it enough times has started to
give me the feel for IBO works, but it is still quite arcane to me
none the less!!)

I noticed that CalculateFields was being called, then I remembered
that recently I had made one of the actual fields in the table a
calculated one.

Once I removed this field from the actual select/update SQL, and had
it only under CalculatedFields, the problem was solved.

I would like to understand this better though...

I thought that when post was called, the calcFields were calculated,
and then the dataset is posted.

But it appears that the dataset is posted, then the cal field is
calculated, and as this field was part of the select/update SQL and
has just changed, the dataset is back into edit mode.

Is this correct? It seems a little backward to me, but I'm sure it's
not, hence asking for further info on this.

Is it safe for me to declare a calc field, which is really the same
as the actual field in the table?

I have just tested it, and all seems OK, but I need to be sure...

Thanks for any further info,
Rgds,
-Ryan