I'll need to get some log files from you to investigate further. Please see the FAQ Where do I find the Flash Player installation log on the Macintosh? and provide all four files (install.log, FlashInstall.log, Adobe_ADM.log, and Adobe_GDE.log) files. Please read through the FAQ before doing anything to prevent you from having to run the installer multiple times to obtain all the required information. The FAQ contains a link to instructions for uploading the files. Once that is done, please post the link to the files in your reply.