Elmar Fudd's Focus Pwoblem

I recently bought an Elmar 5cm f3.5 for my iiic, and the first roll came out all blurry! The lens seems to attach correctly to the body and the rangefinder focus seems to be parallel, but the result is awful. I'm new to both RF and Elmars so I don't know if it's me or maybe something is wrong with the lens. Ive been looking for an answer in past threads but i cant find any that adresses this problem. Please point me in some direction.

was it a 'Collapsible' lens ? If so maybe you had not pulled it out and locked it into position properly.