I have a bit of time at work today and wanted to work up some cards from some pictures I've taken. I happened to have large photos uploaded to my smugmug account so I just right clicked and saved the originals from there. When I open them in CS2 they look dingy. I know this is a classic color space or viewing problem but it's been so long I can't quite remember what I should do about it.
It probably has in incorrect embedded ICC profile that most web browsers ignore, but CS2 is converting the colors based off the profile. Assuming that is the issue, you will need to figure out what profile is embedded do a "Convert to Profile" in the edit menu to fix it.
If you run it through ImageMagick it will tell you the ICC details, or if you post a link to it, I can also check it for you. I'm sure there are other ways to check too, but I'm cranky and set in my ways.