I transferred a Powerpoint 2008 presentation using a USB memory stick from my new iMac (latest OSX) to an older iMac (OSX 10.4.11) but could not open the file either by double-click or from the Powerpoint 2004 application on that computer. The file icon as transferred is a Zip file and when I double-click iI get a window saying 'Archiving file ...' but it doesn't open. Neither do I get an unzipped icon to open. I confirmed that BOMArchivehelper is enabled and exists on the computer. What am I missing?