Alpha Channels are backwards, Help!

Using CS4, when I select an object in a JPG, I want to save it as as Alpha channel.
I choose Select---Save Selection---OK

The selected area in the alpha channel should be White and the deselected area should be Black.
but...I get just the opposite, Black for selected area, white for deselected.

I've looked all over for settings that would cause this inversion but can't find any.
Any suggestions?

If I invert the selection before I Save Selection, it works but that just does not seem the way it should work.

Thanks, Tom B.

Older, but still learning!