I have found the answer and want to share it.
NCO3.0 SAP.net Connector requires that you send ALL of the IMPORT parameters over on the call. The defaults on the parameters are being overlooked. For example, on a BDC there is a parameter called NODATA which is the character you used to denote "no data for this field". I use a forward-slash. That's the default when the BDC is created by SHDB. All of those defaults are worthless when the remote function is called from the .net world. I'm not sure why but the answer is, if you have 20 parameters, send all 20 parameters and set the defaults in your code on the .net side. Do not expect the function's IMPORT defaults to get used. They apparently get overlaid with blanks unless you explicitly set them.
Worked for me!
Crew