Legacy AF lenses on the SDQ

The last outing of my SD14 revealed a new and disturbing tendancy for gobfuls of front focus, subsequent investigations have not yet revealed the reason for this, and it has tipped me over the edge into splashing out on an SDQ and a rather tasty 50-100 f1.8.

The new lens is rather lovely, but I was hoping to be able to get some passable photos out of my older lenses, and I seem to be struggling, I know sigma don't guarantee compatibility, but I have been rather dissapointed so far.

I'd say my two best lenses are my 70mm macro and the 15-30, neither seem inclined to get anywhere near focusing on most shots, does anyone have any tips for improving things?

Also I have two older sigmas which were converted from canon eos mount, neither one wants to talk to the SDQ at all, no information is being exchanged and the SDQ is not operating the aperture or autofocus.  Both lenses worked perfectly on the SD14, the 70-210 2.8 was a bit middle of the road, it really needs a bit of stopping down, but the 400mm telemacro HSM is a real dissapointment, I had hoped it might be workable since it is HSM, I usually shoot it wide open but focussing would be nice.

Has there been a protocol change with the SDQ? or perhaps a voltage change?  It would be a shame if sigma has deliberately prevented older models from working, since I always had the impression that they didn't indulge in artificial limiting of functionality like canon and nikon are prone to do.

I know that some hardcore gear hackers have loitered around here in the past, hoping someone has some suggestions.