I ported some simple v6 BizForm code over to a new v7 project and have run in to an issue. The code is virtually the same as here: http://devnet.kentico.com/docs/7_0/devguide/index.html?api_bizforms_creating_a_new_record.htm

The error is that this line is now deprecated:
BizFormItem formRecord = new BizFormItem(dci.ClassName, bProvider);

The constructor now does not take any parameters. There is a warning but it allows compilation:
warning CS0618: 'CMS.FormEngine.BizFormItem.BizFormItem()' is obsolete: 'This constructor is meant for system purposes, it shouldn't be used directly.'

I can set bProvider later but the 2 ClassName type fields are read only.

When I try to call:

formRecord.SetValue(fieldName,'fieldValue');

I get 'Object reference not set to an instance of an object.' which I assume is because there is no actual BizForm set for the new record so the check against the fieldname breaks.

I am running v7 unpatched. I ran through the doco for the fixes in KIM for 7.0.1 and 7.0.2 and there is no mention of a BizForm fix there.

Am I missing something simple?