How to call my automation method from VB.NET

[Art]

I've developed an Automation Server and I'm attempting to provide examples
for our customers from various languages. I have my C++ example working, but
I'm having difficulting implementing the same example within VB 2005.

My server provides a method "SetTransformArg" which has an argument to
specify the tranform / matrix. With my C++ test program I did the following:

COleSafeArray matrixArray;
DWORD numElements[] = {4, 4};
matrixArray.Create(VT_R8, 2, numElements);
long index[2];
for(long row = 0; row < 4; row++) {
index[0] = row;
for(long col = 0; col < 4; col++) {
index[1] = col;
double val = row + col*10; // make up values
matrixArray.PutElement(index, &val);
}
}
m_SpatialAnalyzerSDKObject.SetTransformArg(_T("Transform in Working
Coordinates"), matrixArray);

I can't figure out how to do this under VB. From VB, the automation server
method is defined as:

Function SetTransformArg(ByVal argName As String, ByRef matrix As Object) As
Boolean
Member of: SpatialAnalyzerSDK.ISpatialAnalyzerSDK

I've tried simple things like:

Dim matrix(4, 4) As Double
Dim row, col
Dim dval As Double
For row = 0 To 3
For col = 0 To 3
dval = row + col * 10.0
matrix(row, col) = dval ' make up values
Next
Next
NRKSdk.SetTransformArg("Transform in Working Coordinates", matrix)

No matter what I've tried, I always get the runtime error:

An unhandled exception of type 'System.Runtime.InteropServices.COMException'
occurred in mscorlib.dll
Additional information: Type mismatch. (Exception from HRESULT: 0x80020005
(DISP_E_TYPEMISMATCH))

Any help you can shed on this matter would be greatly appreciated!

Thanks in advance!