hmm well i was able to return the sigma 20mm, and try on the other sigma 20mm they had, which was a better version (it didnt have the EX tag, but somethin else).
however this too didnt work, i got my camera almost a year ago, i think it should work!
i then tried some lenses at the booth, the KM 17-35mm is nice, maybe it was the good lighting conditions but it was impeccably superfast at focusing, much faster than my tokina! (the downside of older models) i'll have to research quality though as i barely trust anything that isnt metal. f2.8-4 is much better than the 4.5-5.6 on the sony ultra wide.
now maybe theres an older minolta 17-35mm with a 72mm thread, that would be sweet :G.