Not enough detail. C&C please

Just got the first big snow of the year. Figured I'd go take some pics of some yellow leaves that fell on the white snow just to see how I could do. I'm not seeing much detail in them.

I would love to know what I did wrong. I sent my camera, 450D, back to Canon at the end of August as it wasn't getting much detail in the pictures. The lenses had some issues that were repaired. I figured the camera should be perfect now but I just don't know. Perhaps it's the photographer, certainly don't match up to the quality I see on here but I just figured it would be a little bit better.

The first is a resized pic, the second is a 100% crop. I was focusing at the center of the leaf. I would certainly appreciate any pointers.