I was able to get my Sandisk Imagemate Smartmedia card reader (SDDR-55) working today, so I thought I'd post the details for anyone else having the same problem. Someone on another forum had posted something about a particular kext that supported his card reader under 10.2. It was OnUSBMassStorageClass.kext. I did an archive and install to Panther, so I checked my previous system folder. The above kext was in Previous System ->Previous System 1 -> System -> Library -> Extensions. The kext was not present in the Panther System -> Library -> Extensions folder. So, using "sudo cp" in terminal, I copied the kext from my previous system to the new one. After a reboot, I successfully downloaded pictures from the card reader.
I have not noticed any system instability so far, but there is always the chance this could cause a problem later. I do wonder why this kext was left out of Panther. (On a side note, my Panther package was missing disk 2, so it is possible this kext was included in one of the disk 2 packages. I still haven't received a disk 2 from Apple.)