Try to incorporate SuspendLayout and ResumeLayout. I haven't tested it but it might resolve the flickering.

>Here is my code on one of these types of forms I have:
>
>

>Private Sub frmSearchTicket_Move(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Move
>        '************************************************************************
>        ' Procedure/Function: frmSearchTicket_Move()
>        ' Author: Ben Santiago
>        ' Last Revision: 11/17/2005
>        ' Description:
>        '       Limit movement of search form to that of the main MDI form area.
>        '************************************************************************
>
>        '***************************************
>        ' If Main MDI Form Minimized, Do Not Attempt Move
>        '***************************************
>        If objMainForm.WindowState = FormWindowState.Minimized Then
>            Exit Sub
>        End If
>
>        '***************************************
>        ' Check Top
>        '        +44 = Used To Compensate For Title Bar & Menu
>        '***************************************
>        If Me.Top <= objMainForm.Top + 44 Then
>            Me.Top = objMainForm.Top + 44
>        End If
>
>        '***************************************
>        ' Check Left
>        '        +7 = Used To Compensate For Left Border of MDI Parent
>        '***************************************
>        If Me.Left <= objMainForm.Left + 7 Then
>            Me.Left = objMainForm.Left + 7
>        End If
>
>        '***************************************
>        ' Check Right
>        '        -7 = Used To Compensate For Right Border of MDI Parent
>        '***************************************
>        If Me.Left + Me.Width > (objMainForm.Left + objMainForm.Width) - 7 Then
>            Me.Left = (objMainForm.Left + objMainForm.Width) - Me.Width - 7
>        End If
>
>        '***************************************
>        ' Check Bottom
>        '        -7 = Used To Compensate For Bottom Border of MDI Parent
>        '***************************************
>        If Me.Top + Me.Height > (objMainForm.Top + objMainForm.Height) - objMainForm.sbMainStatus.Height - 7 Then
>            Me.Top = (objMainForm.Top + objMainForm.Height) - Me.Height - objMainForm.sbMainStatus.Height - 7
>        End If
>
>        '***************************************
>        ' Record Distance From Top/Left of MDI Parent
>        '    This Value Is Used For When The MDI
>        '    Parent Is Moved. MDI Parent's Move Event Also
>        '    Moves This Form To Continue "ChildForm" Appearance
>        '***************************************
>        If Not objMainForm.IsMoving Then
>            DistanceFromMDIParentTop = Me.Top - objMainForm.Top
>            DistanceFromMDIParentLeft = Me.Left - objMainForm.Left
>        End If
>    End Sub
>