>How do you do this? Do you open the generated class behind the dataset and change the inherits line? If this is so, how do you remember to re-do this when the code is regenerated?

Yes, you open up the the cs file behind your DataSet (e.g., VendorDataSet.cs), and change

    public class VendorDataSet : DataSet {

to

    using OakLeaf.MM.Main.Data;
    ...
    public class VendorDataSet : mmDataSet {

As far as I know, you just have to remember to re-do this manually when the class is regenerated. However, it only gets regenerated when you alter your schema (xsd), I'm sure.

Ric