Bigstock rejection

I started out with Bigstock simply because they would accept the size of photo my camera creates. Many sites require 5mp (five mega pixels) and I can only go up to just under 4mp.
These photos were taken a few years ago with an Olympus Stylus 300.

Above are two rejections due to Artifact Problems. I edited these using Microsoft Picture It! by increased sharpness and saturation levels. I'm new enough to this to not know if they needed editing or not, but one site advised that all photos need work before being submitted. All I've got is PictureIt, so, I messed around with them. It was fun, and I figure if I keep submitting photos, I'll eventually learn.

I think I see the "noise" they are talking about, and I note that the photo properties indicate a flash was used. One of the annoying things about the point-and-shoot is the auto flash. Every time I forget to turn that off before taking photos. I think that may be the problem here. 

Below are the same two photos prior to editing: