High CPU usage while buffering a video

I have a high CPU usage (over 40%) while only buffering this video.

[URL=http://www.album.de/bild/2453155/ie10pre1-flash116602108-marsearth-a.c fm][IMG]http://www.album.de/img1/screen/245/24531555762898.jpg[/IMG][/URL]

a) open this url: http://www.wimp.com/marsearth/

b) pause the video if it starts automatically

c) use task manager or process explorer to view the cpu/gpu usage

reproducible: sometimes

Tested with IE10pre1 and Firefox Nightly 2012-12-29 on Windows 7 SP1

Flash Player 11.6.602.108 and HWA enabled

TestPC: Gigabyte GA-K8NS Pro; AMD Athlon 64 Venice 3200+; 2x 1GB MDT DDR-400-CL2; Club3D HD4670 AGP; Samsung HD103SJ, SyncMaster 204BM