While this remains unresolved, I've found an alternative:
Using the Function Object, create a function "Create Object" with the following action:
System > Create Object by Name (Function.Param(1)) on layer (Function.Param(2)) at X (Function.Param(3)) and Y (Function.Param(4))
Then I use the following script to create the object:
However, I'd like to be able to create objects directly through Python script. This is bit of a roundabout solution...