Diacetyl Rest

So my first lager, a bock, has been bubbling away like crazy for 8 days (at 52-55 degrees). However, over the past two days it slowed to 1 bubble per minute (at most). I took a SG reading 1.012 (the target) and decided to move it to a warmer spot for the diacetyl rest (68 degrees room temp) this morning. Now it has increased to 4 bpm. Just curious, is this normal? When the yeast consumes diacetyl, does it give off CO2 as if it is fermenting sugars? When should I cool it down?

It's normal. I always see increased activity when I pull my lagers out for a rest.

I assume that there is also some sugar for the yeast to consume since it was still bubbling very slowly. But the effect on taste should be negligible.