[Bug-AUCTeX] problems with preview, how it behaves on my system

[jfbu]

I have noticed that a number of people have
reported problems here over the last year or so
with getting preview to work. For many years
I did not upgrade my system and it worked fine
(I used exclusively dvi output)

Here is my current experience after moving to
Mac OS X 10.8.1, with
Emacs 24.2 (Mac Port),  TL 2012 installed,
and the latest version of auctex 11.86 I could fine. 
(which includes a patch related to the way gs is
called). I am using the
normal latex engine for dvi and pdflatex for pdf.

(dvi output): works fine if previews are generated
"for buffer", also when the file is part of 
a multi-file project. Does not work when
previews are generated "for document": in that
case a multipage dvi file is created will all
images, one per page, but next step in processing fails.

(pdf output): fails as above with "for document", a
pdf file is created with one page per image, but next
step seems to fail. Works "for buffer" but only
for a single file document. If from a project with
a master-file it fails, also when asking previews 
"for buffer", contrarily to the dvi output case.

I did not try "previews for region", or "at point".

Everything else in AUCTeX works fine as far as I can tell, 
including direct/reverse search with xdvi under XQuartz and Skim.app 
for pdf. I applied one or two advices found on the net,
including one on AUCTeX's way of
determining if source-specials or synctex should be used,
because I use sometimes dvi with xdvi, sometimes pdf with Skim.
(or pdf with Okular 0.10.5 on Fedora 13 distribution at my office) 

Just in passing I mention that to get xdvi (from TL2012/Mac Intel 64bits) 
to work when launched from Emacs.app 
I had to add a -unique option to the way it is called when 
the source-specials are *not* activated. 

Of course I will post logs of (more or less) minimal examples
if asked.

Sincerely,

JF B.