Deleting Bootcamp Partition Problems

I just upgraded my computer from leopard to snow leopard. Now that the software is loaded I am trying to delete my bootcamp partition. I am using bootcamp assistant but I cannot get past the second screen, and instead of showing me the page delete or create bootcamp partition I get this. "The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows." I want to get rid of this partition but just don't know what else to do, can anyone help me?