Adobe Reader does not play SWF media embedded in PDFs, if SWF version is higher than 6. I get the error "The media clip cannot be played in rhe manner that the author intended. You may need to upgrade your player software or install new player software".
I have installed Adobe Reader 9.3.0 and Acrobat Flash Player 10. Acrobat Flash Player plays all my SWF files without problem in Firefox browser .
If I change version byte to 6 in the SWF media, Reader happily plays it.