Occlusion vs. Lights: Lights Lose

We're having a problem with occlusion and lighting: Frequently, lights that are placed close to or just outside of the mesh for our level geometry are getting occluded so that they never render.

Here's a good example:

The light on the left (not selected) is the same distance from the geometry as the one on the right (selected) but only the one on the left is rendered with occlusion culling on (about 0.05 meters away). The occlusion system seems to be so sensitive that we can't place lights close to walls. Is there any way to reduce this sensitivity?

In addition, our lighting artist would also like to be able to place lights *outside* the level and still have them render (not by more than a meter or two).

Is there any way to do this with Unity's Occlusion system, or is it completely rigid in its handling of light sources?

Thanks,
Luke