Steps to regenerate:
1. Go to http://demo-stable-ofbiz.apache.org/catalog/control/EditProductStore?productStoreId=9000.
2. Go to shopping cart section in the above link and set Allow order decimal quantity field to N.
3. Create sales order and add an item to shopping cart and update the unit price of an item and click on "recalculate order".
Actual: Error occurs like "Quantity in decimal is not allowed".
Expected: Price should be updated.