Pierre, I am shooting with a Sigma 105mm EX macro with the image stabilization on, with the Vivitar extension rings (totaling 65mm). Maybe it's my eye as I am using manual focus and not the AF.
Thanks for the info Brian, I will try having the exposure speed set to 1/200th at a minimum.
When I looked at the EXIF data for those pictures, they ranged from 1/50th to 1/100 so maybe that is also to blame.
I'm waiting for my flash cord to come and then I have the fun of trying to get a bracket to get the flash to the front of the lens.... Fun Fun Fun... 