This is a small section of an image I put in gallery.  The subject is a bird in a photo.  I wanted the background a bit soft and slected the bird, inversed, used gaussian blur to soften the bg.  I used only a little blur so the bird would not look "pasted", which it is not.

There is a slight halo at the boundry of the bird and the bg.  How can I prevent this from happening or lessen the effect?

The selection was done with no feathering.   Any advice will be very appreciated.       TomDart.

There are a lot of ways to do that. You could either cut the bird and put it on a new layer then blur the other layer or you could select the bird and expand the selection by 1 or 2 pixels (select > modify > expand) before inverting.

Thanks, Dreamer.  I will give  expanding the selection a try.    TomDart.