Thanks for the rapid responses, Bob and Cyndee.
When I'm presented with the File Open dialog in PM 6.5 I don't have
the option to choose "All Files." And PM 6.5 won't "accept" the file
if I drag in onto its icon in the Dock or in the Finder.
Also, when I try to open one of the files in inDesign (whether through
the File Open dialog box, double-clicking, or dragging onto its icon)
I am presented with the following error message:
"Cannot open the file 'C&R (001-29).pmd'. Adobe InDesign may not
file format, a plug-in that supports the file format may be
missing, or the file
may be open in another application."
I'm surprised to hear that the .pmd extension is for PM7 files, as
these files are for a book that was published more than 5 years ago. I
suppose that someone could have converted them or something since
then, but I wasn't aware of that. Is it possible that these files are
in PM7 for Windows format? I remember someone once telling me that
files created with PM 6.5 for Mac weren't compatible with PM 6.5 for
Windows, and vice versa. Oy vay, what a pain...