Does your lens glow wide open? I find that for both my 40mm and 57mm f/1.4, they glow quite a bit.
I'll admit I don't quite know what "glow" means, but if it means what I think, I'd agree. I'd almost call it glare.
If I use either one in bright daylight, it's hard to keep it open and compress the depth of field. There seems to be too much light bouncing around the lens/camera cavity and everything seems to get burned.
By contrast, the OM Zuiko 50mm f/1.4 is a lot more forgiving.
But it takes beautiful pix in the shade or indoors, and I like the way it renders the images. During the day, the 40mm is OK stopped down, but at anything below 2.0 it's got to compete with the Lumix/Leica 45mm, and it loses that challenge handily.