"More coarse threading": roughly 100% sure that you're looking at dealing with cross-threading or similar damage from a previous removal attempt (i.e., the threads have mostly been torn out). You might have to resort to brute-force methods to remove the crank arm.

Exage used bolts and washers to secure the crank arm to the bottom bracket spindle, if I remember correctly. Too bad you can't go back in time and tell the person who damaged the threads to remove the washer before threading in the crank puller, or else . . .