the 500px attachment is broken like the other one. No real need for it. I just blew up the 127px one to get it on the market. I'm not sure where the full size of 500px is show. All the images I see on the web are smaller.
Well, I think you need it for Market. I worked for Green Power too, and the requested size is 512x512. As you can ckeck on your descktop, the Toggle 2G Plugin icon is really blurry. You'll need to change it with one wit a better resolution.
It seems that the XDA server corrupts the attachements. Please change the icon from market with the bigger one attached. I'll send you the archive pasword in a PM.