Ok I figured out what it was... before I was having problems with both forestprep and domainprep, then after some research I discovered that these utilities can only be run against the AD controller designated as the schema master. When I originally was loading Server 2003, I was reloading a machine that was previously designated the schema master, and was drying to run adprep on the other domain controllers without any luck. So, I tried loading a separate machine with 2k3, leaving my schema master in place. I ran adprep on the schema master, let it propagate, and I was good to go.
Thanks for all your help.