First of all, this line is not needed:
gdaMyDataAdapter.UpdateCommand = MyCommandBuilder.GetUpdateCommand(True)
...that's because the the SqlCommandBuilder takes the current SelectCommand from the DataAdapter that is passed to it to generate the required InsertCommand, DeleteCommand, and UpdateCommand. Since the DataAdapter was passed by reference, the changes made inside the CommandBuilder are now visable to the rest of the program.
Likewise the following are not needed:
MyCommandBuilder.GetUpdateCommand()
'Below two calls seem to do NOTHING.
MyCommandBuilder.GetDeleteCommand()
MyCommandBuilder.GetInsertCommand()
... for the same reason. You pass the DataAdpater to the constructor of the CommandBuilder, and all of the required commands are automagically set inside the CommandBuilder.