Heres the deal...
There are Compact Flash I and Compact Flash II cards. This is what I *think* I know about them:
CF I is flash memory based. CF II is micro hard disk based and slightly thicker (but same interface).
Seagate used to have 5GB CF II cards that were compatible with just about anything in the old Rios, until people bought these things for $250 just for the hard disk. They didn't like this for some reason, and changed the firmware to somewhat "cripple" the device (make it less compatible with a lot of things).
I recently won an ebay auction for this card. They auctioned it off as compatible with Digital Cameras. They probably weren't aware of the new firmware change. Basically, this is of no use to me since it doesn't work in my digital camera. It is recognized, and works perfectly with windows. I have no idea what else it is compatible with.