Gamespot walkthrough:
Note that there is a pretty common bug in this area, where you'll start a speedkill on the Klompa and get the first strike in, but the screen flashes for the second dagger strike never appears. Apparently there are a couple of solutions. For the first sword flash, try waiting until the end of the flash before hitting the attack button. If you hit the button just as the flash appears, the second one never pops up. Alternately, when you're on the beam leading out to the Klompa, you can try to hit the start-speedkill button, then hold it down while hitting your normal attack button throughout the combo. Hopefully these will prevent you from missing the second dagger strike.