Thanks dburdick, that has helped a lot; I set Radiosity Gain to 0.00 and the glow is essentially gone (see attached image).
I have one question about what the radiosity gain does though. If the value is set to zero, does that mean that there is no Radiosity effect at all? If so is there any value in using GR with the gain set to zero? (ok, that's two questions ;) )