What's with the auto-levels thing? On a quick look through your work here, that seems to be your first resort all the time ... I'd personally want to keep more control in my own hands.
Lighting really doesn't have to be expensive for at-home still lifes, possibly the most expensive piece of kit you need is something to put the camera on - a tripod being the obvious thing, and most controllable. And it's you lighting above all else that lets this shot down. It's the on-board flash that's produced that truly unpleasant bright area on the melon, and the equally unpleasant heavy shadow around it. A simple desk light, perhaps with a simple bit of paper taped over it to soften the direct light, and you'd have infinitely better lighting.
Other than that ... well, focus and detial are fine, you use of USM seems more effective than in your earlier stuff. The actual set-up itself has caused you as many problems score-wise as anything else, including the lighting.
Humourous snapshot for the family, not a very well carried out shot in a photo challenge.
Onboard flash and high ISO hasn't worked well here. Composition isn't bad though, at least it's not dead centre.
Don't like the reflection off the melon, and the shadow is a little strong. Interesting subject matter. It just doesn't motivate me. I do love the tones.