Adobe® Flash® Player "Square" is a preview release that enables native 64-bit support on Linux, Mac OS, and Windows operating systems, as well as enhanced support for Microsoft Internet Explorer 9 beta. That's good news !
Download and install the Flash Player "Square" preview release .
First remove nspluginwrapper and flashplayer-mozilla, after that I move libflashplayer.so to ~/.mozilla/plugins ( I compile firefox myself ). Or move it to /usr/lib/firefox/plugins.
Can confirm that it works with less CPU usage !