Here are some examples from last weekend. It was a cold day with a very cloudy sky. Please judge the image quality here, most shots were taken as test shots.
Not sharp. I don't think it is misfocused, shutter shock or movement from my part?

105mm macro, 1/160s, f/2.8
The one on the left has sharp tail and paws, which is in the same plane as its head. If i recall correctly, there was no subject movement.

105mm macro 1/250s, f/3.2
Very shallow DOF, but sharp @1/125s

105mm macro, 1/125s, f/2.8
Also sharp, now @ 1/250s

105mm macro, 1/250s, f/2.8
Just wanted to test my handheld steadiness. Not bad IMHO!

105mm macro, 1/160s, f/3.2
Am i being paranoid? Any theories or comments are welcome!