Random slowdown in metroid prime trilogy

[drhycodan]

I experience some sort of slowdown in metroid prime, usually when I first boot the game up.  However, what's odd is the game itself thinks it's still running full speed because the audio doesn't crackle or stutter or slow down, just the gameplay.  I first thought I needed to enable optimal performance in my nvidia drivers, but that doesn't seem to help.  Anyone else experience this?