I can get a msgbox to display sCurAccountno but I can't asign sCurAccountno as the text value for Textbox1. So this works:

Public Class Form1
    Dim WithEvents oRecObj As New GoldMine.RecObj

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AddHandler oRecObj.RecordObjectHasChanged, AddressOf ContactChanged
    End Sub

    Sub ContactChanged(ByVal sCurAccountNo As String) Handles oRecObj.RecordObjectHasChanged
       msgbox(sCurAccountNo)
    End Sub
End Class

And this does NOT work:

Public Class Form1
    Dim WithEvents oRecObj As New GoldMine.RecObj

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AddHandler oRecObj.RecordObjectHasChanged, AddressOf ContactChanged
    End Sub

    Sub ContactChanged(ByVal sCurAccountNo As String) Handles oRecObj.RecordObjectHasChanged
        TextBox1.Text = sCurAccountno
    End Sub
End Class

Software/Hardware used: