Vista - bitmap to surface in Direct3d

ok...

This isn't working, and I dont know why, when I pass the resulting
surface to StretchRectangle I get the awsome "error in application"
haha... anyway. Is this not the right way (using .Net 3.5 runtime and
the latest DirectX Dev Kit form March) to turn a bitmap into a
surface?

Public Function img2surface(ByVal img As Bitmap) As Direct3D.Surface
Dim image As Direct3D.Surface
image = New Direct3D.Surface(device, img,
Direct3D.Pool.Default)
Return image
End Function