So I edited your glow map:
like this:
With the following result. Previously:
Now:
As you can see, the glowmap should only include areas that are part of the actual light source, which isn't necessarily the whole lamp. The shapes on the glow map can be very slightly blurred (as I did) but they should not "bleed"/glow over to adjacent areas.
I uploaded my GIMP source file here so you can have a look at what I did.