It stutters and stalls. Audio out of sync. Buttons unresponsive. I get messages that I need to Force reload the web page and that it will cause all open pages to reload. I quit Safari and dumped cache and data in Flash preference Pane.
You've tried everything in your link? You've run the Flash Player Uninstaller and also deleted the files in my link and reinstalled Flash? Also look in HD/Library/Preference Panes for the Flash Player pref pane.
Try another user to isolate system or user problem.