I've used Acrobat 6 to import and create .pdfs for inclusion as images, not thinking about compatibility mode (set by default on acrobat 6 I suppose). When I try to texexec a .tex doc with such pdf inclusions, i get this output : Error: pdfetex (file ./pieces-graphiques-l.pdf): pdf inclusion: found pdf version <1.5>, but at most version <1.4> allowed ==> Fatal error occurred, the output PDF file is not finished!
You could try this:
$ perl -npi.bak -e 's/%PDF-1.5/%PDF-1.4/;' *.pdf
It might/might not work, I do not have any read PDF-1.5 files to test.
You can also use the Acrobat 6 PDF Optimizer (Acrobat 6 Menu: Advanced -> PDF Optimizer) to create PDF files in earlier PDF versions. I usually use "compatible with acrobat 4" which works quite nicely with PDFTEX. I don't quite understand why they didn't make that an option in the "save as" dialog ... Grüße, ulbi