Error with GetOpenFileName under NT (CDERR_INITIALIZATION)

I got that snippet of code from ALLAPI.NET to make the getopenfilename function to work in one of my project. It works just fine under W98 but under Nt 4, it bombs with that CDERR_INITIALIZATION error. What could possibly the problem ? I'm quite new at this and have been looking for a couple of days to no avail. Any suggestions is appreciated.

Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias "GetOpenFileNameA" (pOpenfilename As OPENFILENAME) As Long
Private Type OPENFILENAME
lStructSize As Long
hwndOwner As Long
hInstance As Long
lpstrFilter As String
lpstrCustomFilter As String
nMaxCustFilter As Long
nFilterIndex As Long
lpstrFile As String
nMaxFile As Long
lpstrFileTitle As String
nMaxFileTitle As Long
lpstrInitialDir As String
lpstrTitle As String
flags As Long
nFileOffset As Integer
nFileExtension As Integer
lpstrDefExt As String
lCustData As Long
lpfnHook As Long
lpTemplateName As String
End Type
Private Sub Form_Load()
'KPD-Team 1998
'URL: http://www.allapi.net/
'E-Mail: [email protected]
Dim OFName As OPENFILENAME
OFName.lStructSize = Len(OFName)
'Set the parent window
OFName.hwndOwner = Me.hWnd
'Set the application's instance
OFName.hInstance = App.hInstance
'Select a filter
OFName.lpstrFilter = "Text Files (*.txt)" + Chr$(0) + "*.txt" + Chr$(0) + "All Files (*.*)" + Chr$(0) + "*.*" + Chr$(0)
'create a buffer for the file
OFName.lpstrFile = Space$(254)
'set the maximum length of a returned file
OFName.nMaxFile = 255
'Create a buffer for the file title
OFName.lpstrFileTitle = Space$(254)
'Set the maximum length of a returned file title
OFName.nMaxFileTitle = 255
'Set the initial directory
OFName.lpstrInitialDir = "C:\"
'Set the title
OFName.lpstrTitle = "Open File - KPD-Team 1998"
'No flags
OFName.flags = 0

'Show the 'Open File'-dialog
If GetOpenFileName(OFName) Then
MsgBox "File to Open: " + Trim$(OFName.lpstrFile)
Else
MsgBox "Cancel was pressed"
End If
End Sub