I just purchased a new iMac and copied my iTunes library from my G3 (OS X 10.2.8) i Mac. I was able to use Target disk mode to drag my Itunes library folder on to the G5 iMac. All of the songs copied but I didn't get any of my playlists, ratings or playcounts. I know these are in an xml file and that file was copied (I think) when I moved the music folder. I had the same issue with my photos in iPhoto, got all of the images but no roll numbers, albums or keywords.
Any help would be greatly appreciated.