Problem with external dll

[oki]

Hey,
recently, I've been trying to use Moo (http://www.influenced.net/moodll.php) from within a VB.Net prog, but I'm having problems with the function declaration.

The functions (C++) look like

int __stdcall uptime(HWND mWnd, HWND aWnd, char *data, char *parms, BOOL print, BOOL nopause)

(standard declaration for mIRC's $dll calls - the function doesn't use anything but the data string/char-array, which it does a strcpy() to)

I have my function declaration like

Public Declare Auto Function uptime Lib "c:\moowrap\moo.dll" (ByRef mWnd, ByRef aWnd, ByRef data, ByVal parms, ByVal print, ByVal nopause) As Integer

my test-code looks like:

        Dim mWnd As System.IntPtr
        Dim aWnd As System.IntPtr

        Dim data As String
        Dim parms As String

        Dim print As Boolean
        Dim nopause As Boolean

        mWnd = Me.Handle
        aWnd = Me.Handle

        data = ""
        parms = ""

        print = True
        nopause = True

        uptime(mWnd, aWnd, data, parms, print, nopause)
        MessageBox.Show(data)

but i get a error message:

An unhandled exception of type 'System.Runtime.InteropServices.InvalidOleVariantTypeException' occurred in WindowsApplication1.exe

Additional information: Specified OLE variant is invalid.

any thoughts?