Hi dping28,
The Z should generally mount an SD or CF card automatically. Back in the day of my Rio PMP-300 I know the format of the cards used in Rios was some proprietary filesystem that was only recognized in the Rio. So it wouldn't automount, or mount at all in any other system I tried. Do you know what filesystem is on your SD card? If it has an unusual filesystem on it you may need to help mount out by telling it.
John