Hmm... no change... Is it making a loud whine? It should be silent. I don't suppose you have an extra IRF840 laying around. Also D1 could be damaged too. Both of them got really hot. I would think the coil is ok if you didn't let the smoke out.
I'm just guessing here. Both Q1 and D1 will usually either work or fail completely.
edit: What is your PWM on-time (setting #23 or #24) ? It shouldn't be over 200 in most situations. My clocks have always calibrated around 160-170.