[8.03.403] cost roll up issues

During the cost roll up to determine end item standard costs, I have
noticed two issues...if I want an item to remain at no value in
inventory, I can't code it any way and the cost gets calculated not
only for that item, but for any next level items as well. Is there
any way to stop this? I tried to use the phantom to blow past the
item I don't want costed, but that logic doesn't work either. Also
having a problem with the system not recognizing the costing lot size
and it calculates the cost based on a lot size of 1. Has anyone else
run across these issues?