All I can guess is that:
I have not explained the problem sufficiently, or
everyone has missed something in reading my original post, or
the AutoCaption feature works differently for me than it does for others.
I'll try to address the first possibility.
I presume that this feature was designed to save time/effort in creating a
separate caption for each insertion and to ensure consistency of
format/position/etc of all the figure/table/equation captions in a document.
It certainly is not saving me any time.
When I activate it for the insertion of graphics files, specifying the
built-in settings "figures" and "below", what it seems to do when I
Insert-Picture-FromFile is to place an extra line of left-justified text in
"Caption" style (with no frame or other formatting) a couple of vertical line
spaces below the graphic. This line contains the text: "Figure n"
(n=sequential number of the insertion). This text does not appear to have any
"special" characteristics that I can see/rollover/click on (even if I reveal
the formatting codes), but does have some "magical" properties, since I can
insert cross-references to it elsewhere in the document.
After re-sizing the graphic and setting the text flow and layout properties
(at the moment Top&Bottom flow with 0.4cm gaps and centred in a column), I
centre the Caption text line and all seems fine. If I then shift the graphic
up or down a couple of lines within the document, one or two lines of text
flow into the gap between the graphic frame and the caption. Yes: between the
graphic and its caption. There is no frame around the caption to adjust.
There is nothing but the graphic for the "Select Objects" tool to select for
grouping.
By "playing around" with positioning, I have so far managed to avoid this
problem, making the text flowing into the gap end up just as a single blank
line, but I have now ended up in a situation I cannot change, where the
caption has flowed onto the page following the one where the graphic is
located. Again: the graphic and its caption end up on different pages. Moving
the graphic higher brings the caption back onto the same page, but apart from
this position not being acceptable for this particular document's logic, one
or two lines of text always seem to remain between the graphic and its
caption. If I force the graphic to go onto the next page, it ends up aligned
with the top edge of the "virtual paper" and its caption drops to a couple of
lines below the first text. Any further manipulation causes the graphic to
end up somewhere else in the document, sometimes a couple of pages away,
sometimes behind another graphic (even though the properties of both graphics
initially have the "Allow overlap" unchecked), and I end up having to Undo to
find it.
What a mess, MS!
I wish I could attach an example to illustrate the above explanation.
EB