It's revision 4. The chip on it says 4.5.
Thanks for all the replies and suggestions. Rather than disable 50% of the cards functionality or spend hours trying to figure out why it doesn't like my 3GB drive, I'm going to put it up on Ebay. Since I got my mac, I'm just used to stuff working with the minimum of fuss. I'm just an impatient old codger these days. Besides, I could use the $100 or so I paid for it right now. Too many Christmas presents to buy!
Thanks again for all the helpful advice! This is a great community.