Why are my Kethane tanks not filling?

I've been playing around with the Kethane resource mod, and I believe I've met the requirements to be able to extract Kethane from Mun.

I've deployed satellites around Mun, in a rather nice fashion, if I do say so myself:

After I had scanned the area, I landed my miner in a dense concentration of Kethane deposits:

So far, so good. The landing was a bit rocky, but it survived intact. I deployed my drills, but they're not gathering Kethane:

According to the Kethane Fuel Routing thread, the fuel tanks work just like Monopropellant; they don't need fuel lines. As long as a drill is attached to the same entity as Kethane fuel tanks, they'll be filled. So what am I missing here? Why can't I gather Kethane?