trovo qui
http://tex.stackexchange.com/questions/41902/creating-a-pdf-of-version-1-5-and-using-the-etexcmds-package
la seguente risposta che mi accorgo essere targata egreg 🙂
That info message is perfectly normal.
The current version of pdftex is 1.40 (it’s independent of the PDF version); as far as I know an \expanded primitive was planned for pdftex version 1.50, but I don’t know if it will ever see the light.
The package etexcmds checks for the existence of \expanded and doesn’t find it as a primitive, so it tells you.
As of version 1.40, pdftex can output PDF 1.5 and setting \pdfminorversion=5 does just that. However, this is the default as of TeX Live 2011 and, I believe, also MiKTeX 2.9.
Però i post erano del gennaio 2012. Stessa cosa attualmente?
grazie
m