Close
Humm... from what I know the initial image should never increase in size if the original and the newly saved image are the same file type and you haven't added any artifacts and all you have done is simplified the image such as removing artifacts and adjusting the color depth.

I think it has to do with the program you using to edit the image with, the compression is different. Usually for programs such as CS2 which is what I use, the save has no options for compression quality and defaults to the normal, unless you are using the save option in which you can adjust the compression of quality to size ratio.