Yes, the current version of the software doesn't support P3D 4.0, because it requires some features from 4.1, so we had to compile the software using the 4.1 SDK, and the 4.1 SDK is not backwards compatible with 4.0.
Is there a special reason why you are still running P3D 4.0 ? It was almost unusable with GSX, due to the missing/black textures bug, which has been fixed in 4.1 only.