A filename with MP3 extension will not get loaded onto the iPod. Renaming the file to mp3 allows the file to be loaded onto the iPod. Not really the end of the world, but it certainly was annoying. The fact that the capitalization of the .mp3 extension causes some files to load and other to not load is exasperated by the error message which says the files cannot be converted or interpreted or whatever. These files with .MP3 extensions play fine with mplayer so clearly the files themselves were not the issue as well as the fact that they loaded fine when they were renamed.
If possible, please either fix the error message calling attention to the case sensitive nature of the extension, or make the extensions case insensitive.
Thank you very much