CRE / OSC Backend Problem

Fix occurring problem on Back end of CRE / OSC online website. Problem occurs when editing an existing order, if a product is deleted or refunded from an order the total adds the TAX figure onto the new(Edited)order total, so the figures dont add up correctly, Original Order = Order Total = Sub total + shipping + TAX = Total. Edited Order = Sub total + shipping + TAX = Total + TAX. This is supposed to be a common problem with CRE Loaded. I require the info to Fix this problem, If it works I will then pay you.