This happened to me as well tonight 12/16/13

I have had this problem with the crowbar as well. Died toe to toe with a zombie while spamming attack but not registering any hits

I also have found this to be the case. was toe to toe with a zombie, swinging away with crowbar, and no hits registered. I am not sure if i had pressed spacebar to be in attack mode or not, but if I can swing, it should register, or i should not be able to swing if not in attack mode.