Getting MP3's to default to WMP11-64bit

[S.SubZero]

I set up Ultimate 64-bit on my laptop yesterday. So far so good, but this is irking me.

I currently have WMP11-64 as my default media player, thanks to a tweak in the x64Components codec pack. My videos now fire up in WMP11-64, whether they work or not. Great. However, my mp3s seem to be completely ignoring this setting, and continue to fire up in 32-bit WMP11. I tried changing the default program option several times, but it ignores this.

Is there a registry tweak or more reliable way to change the default mp3 player to WMP11-64?

(And why does MP11 take like 7 seconds to start playing? What's it doing?!)