What you are doing should work. My test brought the data into a dataset and I could loop through the rows and return each column's data. The error message you a getting has nothing to do with executing the parameterized query itself.

"Retreiving the schema for Oledbdataadapter1 failed! No value given for one or more parameters."

Please tell me you are NOT using a VFP database/table and the VFP OLEDB provider. This is a known problem with the VFP OLEDB provider. Basicly, you can't do anything in ADO.NET that requires retreiving a table's schema such as using the command builder object or generating a dataset using the wizard in the oledataadapter.