Check your Shadow Map size:
1. Open the Invigorator Options window.
2. Open the Invig Prefs dialog
(there is a "User Prefs" button in the Object tab below the 3D preview area)
3. Check your Shadow Quality value.
Higher numbers are better, but may make for slower renders.
If that doesn't help, feel free to send me the project. I'd be happy to take a look.