I downloaded two of your photos: GWAR_3013.jpg and CHUD_06.jpg and opened them in PhotoShop. The first image seems to have an embedded Adobe RGB (1998) profile – great for print but pretty bad for the web. It looks fine in Safari and fine in PhotoShop because they both do color management but it looks washed-out in other browsers and in the gallery.
The second image seems like it has an embedded sRGB profile.
Try converting GWAR_3013 to sRGB then saving it with no embedded color profile. If you are using PhotoShop, it's Edit Menu > Convert to Profile and set Destination space to sRGB IEC6 1966-2.1 then uncheck the Embed Color Profile box in the Save for Web and Devices dialogue. Then upload the no-profile image up to the gallery with a new file name and compare it with the one that's already there.
If you'd like to know more about color management for the web and you can cope with the headache then take a long, slow look at http://www.gballard.net/psd/srgbforwww.html
SimpleViewer Support Team.