Zoho CRM API insertRecord Invoice difficulties

Zoho CRM API insertRecord Invoice difficulties

I have spent a good deal of time trying to get insertRecord/Invoice to work through the Zoho CRM API without success. I have been able to make a number of other API transactions successfully, but the invoice insertion is not working. In pursuit of this, I have already:
- Read the help pages thoroughly, including the API description, API examples, and field requirements for Accounts, Products, and Invoices.
- Reviewed and followed other forum posts relating to invoice insertion.

I understand that something may be missing from or included in error in my XML, but in spite of trying several variations, nothing seems to fix the problem. The message I get is:
<error><code>4600</code><message>Unable to process your request. Please verify whether you have entered proper method name,parameter and parameter values.

it is apparent I don't know the proper parameter values, but there is no concise definition of these that I can find online - Is there an API specification that details these?

Anyway, I am looking for help. The complete HTML/XML string I am presently using, not including my authtoken, is:

  1. https://crm.zoho.com/crm/private/xml/Invoices/insertRecord?authtoken=[authtoken]&scope=crmapi&newFormat=1&xmlData=
        <Invoices>
            <row no="1">
                <FL val="Subject">1234</FL>
                <FL val="Invoice Date">2014-12-04</FL>
                <FL val="Account Name">TestAccount</FL>
                <FL val="Sub Total">10</FL>
                <FL val="Grand Total">10</FL>
                <FL val="Product Details">
                    <product no="1">
                        <FL val="Product Id">1199269000000183003</FL>
                        <FL val="Product Name">DollarPerUnit</FL>
                        <FL val="Quantity">10.0</FL>
                        <FL val="Unit Price">1.0</FL>
                        <FL val="List Price">1.0</FL>
                        <FL val="Discount">0.0</FL>
                        <FL val="Total">10.0</FL>
                        <FL val="Total After Discount">10.0</FL>
                        <FL val="Tax">0.0</FL>
                        <FL val="Net Total">10.0</FL>
                    </product>
                </FL>
            </row>
        </Invoices>
The Account and Product were both manually created in Zoho, and I extracted the XML for the using an API transaction, so I have reason to believe they are fully correct.

Can someone provide some recommendations about what to change or add?
Thanks...