Tuning Issues

I turned on my model D today, and decided I needed to tune it. When I got to oscillator three, it would not get the right pitch. The pitch of ocs 3 does not go low enough to be in tune with the other oscillators. Has anyone experienced this problem and can anyone help me?

I let my moog go for a while, and then came back to it and tuned it again. It seems to be working now, but if anyone knows what happened please reply.