Unfortunately, Breeze applies some rather heafty compression
on bitmap images, including gifs/jpgs and pngs.
Others have reported that you can improve detail of
screenshots a bit by using Captivate to capture the screenshots and
then export the imagery as a .swf. Then, go back to the Breeze menu
and trace down to the Insert Flash option to import the swf created
in Captivate. Results are usually better, but it does require
having to take an alternative approach. And for folks who don't
have Captivate, it might not be a practical approach either.
Two other possible solutions, but both require the right kind
of software to do it: If you have other applications that export as
.swf (like Illustrator, Freehand, etc), you might want to try
importing your screenshot and then exporting as a swf from there,
or you could do the same thing right from Flash if you have it.
Hope that helps!
Rob