here are answers to questions regarding Leopard. i'm not at either of my Macs at the moment (or until i return from a trip) so i can't paste the snippet until i return.
the instructions listed above almost work but you need to change the case.
first, find the raw.plist in the rawcamera.bundle /System » Library » CoreServices » RawCamera.bundle » Contents » Resources/
what i did is copy the raw item for the D-70s and then renamed it to Epson R-D1
note that this has changed from 10.4 where everything needs to be in all caps.
it's important that you set the permissions for raw.bundle otherwise you can't save the raw.plist
once the raw.plist is saved, run the following command in terminal:
openssl dgst -sha1 /System/Library/CoreServices/RawCamera.bundle/Contents/Resources/Raw.plist
the resulting data key must be pasted into CodeResources. paste it at the top, not the bottom. the key length is exactly the same.
once that was completed (and i properly had the case in th eraw.plist) the red 'unsupported image' screen was instantly replaced by my image. i didnt need to reboot.