Virgin Islanders were still trying to make sense of new package delivery processes Thursday that has caused widespread and vexing delays over what often amounts to pocket change. Delicate prom dresses, clunky auto parts, vital medicines, high-tech gadgets — everything shipped by expedited services like DHL, FedEx, and UPS has been backlogged as the territory works out a system to deal with changes in federal rules gumming up the previously fluid system.