Not enough processing power? Graphics card too slow?
I use a program called SplashPro for playback, which works very well.
Anyway, I have experimented with having the cam mounted on top of my helmet. It looks goofy but gives really good footage, plus your neck works as a shock absorber, so no vibrations. The downside is that the wind noise is ridiculous.
I have also used the suction cup mount, on my fuel tank. That also works great although, due to the colour of my screen, everything looks blue! On the positive side, the wind noise is greatly reduced.
I am thinking about trying a mount on the front of my screen. I know the sound will suffer but the footage should look great.