GetComboBoxInfo - PInvokeStackImbalance

Hi, I'm trying to use the GetComboBoxInfo API to customize the position of combo box list, but i get amn MDA stack error using it ...

PInvokeStackImbalance was detected
Message: A call to PInvoke function 'MultiColCombo!WindowsControlLibrary1.MultiColumnCombo::GetComboBoxInfo' has unbalanced the stack. .....

arrrg ...

I've converted the code to VB6 format and obviously i don't get the MDA PInvokeStackImbalance error but it must be having the same problem because I don't anything returned in the COMBOBOXINFO structure

Am I doing something wrong .... is this an issue with my system .... etc.

any help would be appreciated ! thanks

code is as follows ....

Imports System.Windows
Imports System.Runtime.InteropServices

Public Class MultiColumnCombo

Inherits System.Windows.Forms.ComboBox

Public Structure WINDOWPLACEMENT
Public length As Integer
Public flags As Integer
Public showCmd As Integer
Public ptMinPosition As Point
Public ptMaxPosition As Point
Public rcNormalPosition As Rectangle
End Structure

Public Structure RECT
Public left As Integer
Public top As Integer
Public right As Integer
Public bottom As Integer
End Structure

Public Structure COMBOBOXINFO
Public cbSize As UInteger
Public rcItem As RECT
Public rcButton As RECT
Public stateButton As UInteger
Public hwndCombo As Integer
Public hwndEdit As Integer
Public hwndList As Integer
End Structure

Private Declare Function GetComboBoxInfo Lib "User32" (ByVal hwndCombo As Integer, ByVal CBInfo As COMBOBOXINFO) As Integer

Sub New()
MyBase.New()

End Sub

Private Function GetComboListHandle() As Long

Dim CBI As COMBOBOXINFO
Dim hMe As Long
Dim lCheck As Long

hMe = MyBase.Handle

CBI.cbSize = Marshal.SizeOf(CBI)

lCheck = GetComboBoxInfo(hMe, CBI)

GetComboListHandle = CBI.hwndList

End Function

Private Sub MultiColumnCombo_DropDown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.DropDown

Dim hListBox As Integer
Dim wpListBox As WINDOWPLACEMENT
Dim newTop As Integer

hListBox = GetComboListHandle()
GetWindowPlacement(hListBox, wpListBox)
newTop = wpListBox.rcNormalPosition.Top + 150

MoveWindow(hListBox, wpListBox.rcNormalPosition.Right, newTop, wpListBox.rcNormalPosition.Width, wpListBox.rcNormalPosition.Height, True)

End Sub

End Class