I encountered no problems when resizing allows MDIForm, when running this code below:

Private mHeight As Long, mWidth As Long
Private Sub MDIForm_Load()
mHeight = Me.Height
mWidth = Me.Width
End Sub

'disable mdi form resize
Private Sub MDIForm_Resize()
Me.WindowState = 0 'Normal
Me.Height = mHeight
Me.Width = mWidth
End Sub

when I press MinButton of MIDIForm not. can change the code above to just have two functions: do not allow to resize and allow MinButton (or allow MaxButton) of MDIForm it ?