I was reducing the size of an image for the Web and at "Quality 7" it was going to be 350.2kb. I needed it to be less than 250kb so I reduced the setting to "Quality 6" only to see the saved size go up to 257.4kb.

Does this odd increase in ultimate size happen very often?

I re-checked it a few times and got the same results. Eventually had to settle for "Quality 5" (203kb) to get under 250kb. It was the pic of the male in this post
http://www.ausphotography.net.au/for...ad.php?t=27214