Hey Daniel, I can confirm that I too have the same issue in Maya 2011, so it's most likely a "feature" in the software.

However, just so you know, the Maya software renderer isn't really recommended in many cases, as it's so bare-bones. Glow is really caused by particulate in the air, and the exposure of the camera. Therefore, you can create a nice flow effect using environment fog in something like mentalray, or Vray, incandesence, and gi.