I believe the problem lies outside of the code you have shown us. It is the call to the /CurrentSupplies/menu action that is the problem, not the forward. Search your JSPs and html files for a link to /Current Supplies/menu or /Current Supplies/menu.do.
One thing that will cause problems in the configuration file you showed us, though is:
Originally posted by Pat Peg: path="/app/ currentSupplies /main.jsp"