[Sonofswin]

Yeah, I had the same kind of problem when I painted mine.

Looking at all the high heat paint in the store, most of them had, "Don't use on chrome" written on the can - so I picked one that didn't. It still would 'crack' when it dried, showing bits of reflector here and there. (I hung it up in a shack for painting and drying, so it wasn't touching anything.) I eventually ended up putting 4 or 5 coats on it - letting it completely dry between each one and there are still some very small cracks in the paint. Fortunately it isn't obvious unless you stick your face right in front of the light.

I'm not sure if it would work or not, but if I did the project again I would use a really light grade sandpaper to score the reflective surface before painting. You wouldn't want to go too deep or you'd end up with the chrome flaking off, but if you put a couple layers of paint on it I don't see why humidity or what-not would cause flaking.