Sandisk Compact Flash problem

I have an older Canon Digital Elph S250 digital camera that uses compact flash media. The CF card can be read fine through a card reader on my desktop Windows XP computer. But when I try to read the card on my Mac using a CF USB reader, it tells me that the drive cannot be read by a Mac. The file system used appears to be FAT 16, which is an older DOS file system. Any ideas about this? Do more modern cameras with a different kind of flash card use a different file system that can be read on a Mac? I would like to be able to read the cards on either of my computers. I want to load the pictures on the desktop since I have automated backup there, but I sure prefer to use my Mac to look at and manipulate the photos. But I don't want to have to transfer from one computer to the other every time over my wireless network.