Linda From Maine wrote:
A note re size: the one I edited was about 2,000 pixels wide, which makes a nice size for many monitors. The larger the dimensions, the less sharp they look in the thumbnail, because they are compressed to a mere 600 px wide.
Gotcha, Linda...I think that's the answer. Only here on hedgehog when editing with Topaz DeNoise have i noticed this! You amaze me sometimes (even if you were in the Navy)