Absolutely nothing to do with your image or your monitor, all to do with PSC and how it downgrades the quality of the image.
To create the small img, it first resizes your pic to fit in the 'vote' screen, then compresses it to get the lightest (k'byte wise) possible img.
To recreate it try this :
resize your original img in photoshop to 550px wide, keeping the aspect ratio the same, then hit 'save for web'
You'll have to drop the Jpeg quality all the way down to
40 to get the same quality img that psc uses on its comps!
You end up with a file around 25k, that's fantastic for a website that is paying for huge amounts of bandwidth but doesn't do your image any favours.
The only work around I can think of is to not use such large, light gradients in your background. The compression gets very lazy when it sees so much of a similar shade, you're better off using much darker colours which can hide artefacts better or having a more textured bkg that won't be able to be compressed so much.
And what the hell are you talking about pie for now
I just went and wrote all that at 1.30am and you turn the topic around on me! Sonofabitch!