Over the last 1000 ( approx) Sales Orders - about 4 or 5 of did not add up correctly. We find the problem when customer billing or credit card charges are incorrect, and we get calls from customers. 

The problem is the Sub Total will be incorrect, (it does not add the product totals correctly)  which makes the sales tax calculation incorrect and of course, the Grand Total will be incorrect. In each case, as our team goes through the Sales Order details, they put the page in edit mode, check all the entries, tax rates etc, and when the save they Sales Order, it will add correctly and the problem is gone. However, the damage has been done, i.e. irritated customer, phone calls, follow up, etc.

 As we understand it, the Products section  area of the Sales Order immediately adds the product totals as the user constructs the order. Totals calculations are not triggered by the save or refresh buttons.

Has this problem been reported by anyone else?