managed-directx

Missing Direct3D.dll dependency while using MDX

I have taken a perfectly working MDX piece of code to Windows 2008R2 (all DX drivers installed) and am getting the following, rather bizarre, error. Any idea what this could mean? System.BadImageFormatException: Could not load file or assembly 'Microsoft.DirectX.Direct3D.dll' or one of its dependencies. is not a valid Win32 application...