Sorry, mate. Couldn't resist! Joking aside, you say you've dropped it? Are the yokes (trees) steel or alloy? I'm guessing the latter. Slacken the yokes off, and try again. If all goes well, you've simply had everything done up too tight, and miss-aligned. If still no good, leave the yokes in the bike, remove the legs, and take a measurement from beneath the top yoke, (where the stanchions go 'thru), to the top of the lower yoke, at the same place. This'll show if the yokes are bent. Or, remove the top yoke, sit it on a known flat surface. Both ends should have contact. If pressing down on one side creates an air gap ... another indicator your yoke is bent (twisted)! I wouldn't recommend trying to straighten the yoke(s), as they're easily available from breakers.