I dropped my Tokina last week on pavement, (fell out of my bag), anyway, I checked it over and there was no sign of visable damage. Well today I went to put it on for a shot and it was very hard to seat on the camera. Also hard to turn to remove. Everyting still works on it and the camera still recognizes it, it still focuses & takes images. Not sure how it hit, both lens caps were on and I have checked it very closely with my 24-70 and cant really see any reason for the now tight seating. Anybody had a similar experiece and know what to look for?