Files have their File Type and Creator stored in their resource fork. SDII files should have "Sd2a" (Sound Designer II application) for Creator, and "Sd2f" (Sound Designer II file) as the File Type. If double clicking on an SDII file doesn't launch SDII, or if the file is displayed as a Decompression Scratch document in the Finder:- Desktop file is corrupted. Rebuild it with [option]+[command] + Restart, or use TechTool to delete/create it.- Bundle Bit resource is missing or damaged within the SDII file. Use Disk Doctor or other utility to repair it.