Real-time Curiosity Simulator with Landing Preview

This is a great link, thanks. I'm watching it and I have a question about reentry (should apply to all capsules, like Apollo, SpaceX not only MSL): basically, how is this thing stable?

I see the animation and how the capsule twists and turns, and I'm nervous, why doesn't the capsule destabilize and start to tumble? It's not spinning (like a bullet) so how come it stays heat shield down?

Perhaps some kind HN-er with aerodynamic knowledge can write a brief answer for the layman (I'm sure others here might have the same question).

Thanks

This doesn't work in Linux. Not in Firefox, not in Chrome. I'm using Java 7 + Icedtea 7 plugin. The plugin starts Java, but it sits there chewing 200% CPU time and doesn't do anything for 10 minutes.

This is a Java development box, and I tried everything I could think of to fix it. Obviously, other Java apps (even LWJGL using ones) work fine.

Edit: I tried getting it to work under XP in VBox using VBox's guest drivers' OpenGL passthrough, it still didn't work.