Itronics - thanks for your help. It's seems that what you are explaining is exactly what I've done.
I am in the US, where each state has it's own tax rate. So I set up 3 Tax Groups, call them Group A, Group B, and Group C (one for each state our customers are in), and one for Tax Exempt customers. Each of the 3 taxed groups only has one rate....the rate that applies to their state. So Group A is set up for Tax A at 6%, Group B is set up for Tax B at 6.5%, and Group C is set up for Tax C at 7%.
The customer in question is not tax exempt, therefore I selected the appropriate tax group (Group C) in the customer branches setup. Their state is at a 7% tax rate.
This is a "Direct Delivery" entry, but it seems to work the same if I try a Sales Order entry. The order has only one item at $263, and a quantity of 4. So the line item total shows $1,052.00, the sub-total shows $1,052.00, Shipping is $0. All good so far.
Then the tax line shows the tax group and $68.882 for the tax.....which is NOT 1052 x .07. It should be $73.64. The Amount Total line still shows $1,052....which I understand (from reading the many posts on this topic) could be showing the total "value" of the goods in the order....which would exclude tax.
The real problem is that once delivered and invoiced, the invoice shows $1,052 on the TOTAL INVOICE line...so nowhere does the customer know the actual total to pay..... which should be 1052 + 73.64 = $1,125.54
Thanks again for your help....believe me, I have tried figuring this out myself, but tax in this application is a fairly complex chain of included files and called methods on objects that are bounced around quite a bit in the code.