Why won't my gas logs light?
Turns out, it was some sort of safety mechanism (though I'm not sure what it was for). I turned the logs back to off, waited for the pilot to go out, then kept waiting. After a minute or so, there was an audible metallic click/clang, like some sort of spring-loaded mechanism disengaged. I then was able to re-light the pilot, and turn the gas logs on with no trouble.

So, for anybody coming in the future, the procedure for lighting/using this type of gas log unit appears to be:


Turn the knob to "pilot"
Depress the knob, and hit the starter button until the pilot lights
Keep the knob depressed for 30-60 seconds so the pilot can heat the thermocouple
Release the knob
Turn the knob counter-clockwise (without depressing) towards LO, then HI. If the knob won't turn, turn the knob to off, wait 10 minutes, and try again.
To turn the logs off, turn the knob clockwise (without depressing) towards LO, then pilot. You don't actually need to get close to the pilot setting - about halfway between LO and pilot will be sufficient to turn the main part of the logs off, while keeping the pilot lit.


Hope this helps somebody in the future.