I've just installed Photoshop CS3 on 10.4.x and was unable to open .NEF files from my Nikon D300 or .DNG files that I converted. I upgraded to 10.5.1 and reinstalled Photoshop and still nothing. I went to Adobe's Mac support site and downloaded the most recent camera RAW plug-ins 5.8 or something, then when that didn't work I went back to 5.1 that I knew worked for me on Windows. Both show up as a .plugin file and when clicked I am told they are not recognizable (though they have the right icon). When trying to open .NEFs through Photoshop, they are no longer grayed-out, but the program does nothing when I try to open them or .DNGs. I tried to install my Nikon NX software which says Windows/Macintosh on the disc. That froze up and wouldn't let me eject. I tried 8 of the 10 wiki strategies to "force eject" before I could finally retrieve the disc and get back to where I started. I'm about ready to pack everything up and send it back... better the devil I know.