MDK2: Framerate issues (both too fast AND too slow)

[predcon]

Something is seriously wrong with the way MDK2 is running on my PC. When I set all the display settings to maximum, and then click "Test Settings", the test demo runs like a video in Fast Forward, and reports an average framerate of ~630FPS. That's triple digits. But when I actually play the game (even though the title cards zip by), the intro cine runs just fine, but after it cuts to the part where Kurt is about to jump out the airlock of the Jim Dandy, it slows down to a snail's saunter. The words "Jim Dandy, Earth Orbit, 8:59am" appear one letter at a time, each letter coming every fifteen seconds (even though the "blip-blip-blip" noise that accompanies the appearance of the letters plays at full/normal speed). I tried running the game in Compatibility mode with XP w/ SP2, but nothing changed.

Turning off Hardware T&L didn't change anything, neither did changing the CPU Affinity to one core. After waiting about half an hour for the "The Jim Dandy blah blah" text to finish typing, the skydiving minigame ran normally, after which I had to wait another length of time for the "Aboard the Alien Minecrawler" text to finish. When it was done, gameplay ran at normal speed, except for a couple of little things. Like, the "ejecting brass" from Kurt's chaingun came out like Victoria Falls, and reached it's sprite cap in two seconds (I could still fire, but I had to wait for the brass that was laying on the floor to disappear before more would show up). Also, pick-up icons like the first Grenade in the tutorial section spun around like a certain cartoon Australasian marsupial.

So to recap, I've got bits that run like they're on crank, I've got bits that run normally, and I've got bits that run slow enough that elderly drivers give them dirty looks when they pass. There doesn't seem to be any rhyme or reason, and the usual solutions don't work.

Windows 7 x64
AMD Catalyst 11.6


{EDIT}
Hold up, I got it. I just had to switch "Vertical Refresh" in the Catalyst menu from "Off, Unless app specifies" to "Always on". Talk about "Last place you look".