In all versions of DT, including 2.0, DT has never once included a PDF in my autogroups. I posted about over two years ago:
viewtopic.php?f=3&t=3637&hilit=autogroup
and got the impression this was not normal. I am just now getting back to converting my files to PDF and forgot about this issue. Now, once again, the Autogroup function simply does not work on PDF no matter what the scenario (imported, converted, etc.)
Since this is now a problem across multiple versions, I have trouble believing the problem is on my end so it would be helpful to hear from other users as to whether or not they can get PDF files to autogroup