blur tool not working

Here's a way to blur part of a picture using a "clipping group".
In this example I blurred the background leaving the flower in focus:
 <http://www.pixentral.com/show.php?picture=1DZorzpN09eU8ilzB8O1bwjecD6RLb>
;

1. Duplicate the Background layer and apply a Gaussian blur to the new layer.
2. Add an adjustment layer below the blur layer, but do not make any adjustment
- just click OK. It doesn't matter what type adjustment layer; the only purpose
is to get the mask available for the next steps.
3. Group the blur layer with the adjustment layer.
4. Set the foreground/background colors to the B&W defaults.
5. On the adjustment layer use the Brush tool and paint with black to mask out
the blur, with white to restore the blur. Use a soft brush to get a smooth
transition between the 2 portions.

Here's another version of the clipping group:

1. Duplicate image layer and apply Gaussian Blur to the duplicate.
2. Create a blank between the two.
3. Group blur layer with the blank layer; this temporarily removes the blur.