I don't have much experience with threaded headsets. I bought a bike with one last year and never paid much attention until I recently decided it would be a good idea to replace the bearings and clean and put new grease in. After disassemble and putting it back together I have noticed that I can't tighten the locknut all way down to the Top race. There is always a few threads showing. Is this big deal?

There is a very thin keyed washer above the top race but no spacers. I do have a threadless spacer above the locknut for purely aesthetic reasons because I have a 1 inch to 1 1/8 adapter on it. Even though there are a few threads of the steerer showing I seem to be able to get good preload and I can't loosen the top race without loosening the lock nut first even though they don't make contact