User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.1.8) Gecko/20071008 SeaMonkey/1.1.5 Build Identifier: XULRunner Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; de-DE; rv:1.9a9pre) Gecko/2007102008 XPInstall installs files with file permissions set to read-only for the owner. When trying later an update installation fails with error code -215 because the owner is not allowed to modify the files. If I unzip the packages with the built in zip of the Mac the file permissions are set correctly to read permisson, write permission and execute permission for the owner. So the problem is not caused by the package but by XPInstall. There is no such problem on MS Windows. Reproducible: Always

Over to Core -> Installer XPInstall