Can't get my timing right

I'm trying to set my timing on a Mazda b2200 93 base model. I have my cam at 1 tdc and my crank at tdc. But when I try to install my belt it wants to move the crank cause the teeth aren't matching up. But it doesn't seem to be the belt because even if I move the belt a tooth one way or another it seems to be too far off either way? I read how to do the timing belt on Mazda truckin.com and the Arthur mentioned something about the belt having lash? What does that mean and could that be a problem I'm having?

Anytime I did a timing belt on these trucks I would set the lower pulley one tooth off counterclockwise so that when I rotated the pulley clockwise (to take the slack to the tensioner side) it would line back up again. Hope this helps.