Uploading help

I was planning on uploading the last tima comic he had for download,

http://tima.egloos.com/1838081 (winter one)

but I am getting,

Error: Sample couldn't be created: Unsupported color conversion request

as an error.

The files are jpegs.

Well, it's a JPEGlib error occurring somewhere in here. It seems that it usually has to do with JPEGs being saved in odd color spaces like CMYK, but GIMP tells me these files are RGB, so I'm not really sure what's going on.

I have also encountered that error before, so I have to download the image from the artist's home page, re-saved it as PNG-24 in Photoshop, then uploaded.

Doing that makes the over all colors changed a bit (looks dimmer). I don't know if there's anyway to preserve the original color?