I have now had the API upgraded to API Version: 220.127.116.11, it looks good and the issues I had before have now been resolved.
One glaringly obvious issue though, the "productsAdded" option has been removed from the "Create Opportunities" API call (see API documentation, it is no longer there). I cannot find in the API an independent "add products" and "associate to opportunity" API calls. How do I know add a product to my opportunity?
Please can you answer ASAP please as I've been trying to get this API integrated for weeks now.