>DataRow rw = this.oPsTest.NewRow();
>rw["keyno"] = 1234;
>this.Save();

>The insert fails because keyno is not getting the desired value.

I'm assuming this code is inside a WebForm/WinForm and oPsTest is your BizObj. My guess is you have a control that binds to "keyno" and when you call this.Save() the binding mechanism accesses the value of that control and puts it into "keyno" overriding your code above.

This may be a solution:

DataRow rw = this.oPsTest.NewRow();
rw["keyno"] = 1234;
RaiseBubbleEvent(this, new OakLeaf.MM.Main.Web.UI.mmRegisterBoundControlEventArgs());
this.Save();