Light dome is causing holes/non white pixels in alpha

[SonyBoy]

Headline says it all. At first I thought this was some conflict with the physical sun and sky in the scene, but even deleting them doesn't fix the issue. I've never seen this before. This is a vanilla light dome with a simple color value and an intensity of 10. Can anyone offer any suggestions?

Update: Never mind. The problem was in the model, nothing to do with the light dome.