Take a look at the DPReview Minolta forum FAQ:
http://www.pbase.com/mtf_foto_studies/mtf_faqSome general suggestions include turning off the ability to adjust focus after the AF is done. I recall a fairly lengthy thread over on the DPReview Minolta forum about people having this sort of problem and turning off this feature helped. Also, be sure that you have the latest firmware (v1.12 - check your EXIF information to confiirm).
Be sure you aren't asking the impossible of the AS system too; it is only going to help a couple of stops over normal (1/focal length) unless you hands are VERY still.
The only way to be sure is to set up with good light on a tripod and focus on something like a newspaper or a brick wall and test. Eliminate any technique problems this way (tripod, careful setup) and then work from there.