In case anybody else runs into this for Update operations -
in stepping through the Update process (Listview EditItemTemplate) , the runtime instantiated my business object using it's default constructor even if I supplied a fully parameterized constructor, so it seems logical that, if you are passing a BO instance to the Update method you defined, it would need accessible BO properties with names that match those used when it first retrieved /bound the data.
ie - if it doesn't have a complete correct parameter list in the Update statement how else would it map the UI input to the update properties?
I haven't tried it, but I suspect that if you do specify a full parameter set in the update definition (jnstead of a BO instance) it would still need to know how to map the parameters to the properties and since you can't name them identically, perhaps positionally.
If I am wrong I am happy to learn :-)