basically the long pieces that look like spikes on the maguras, touch as soon as you slide them onto the bosses.......this pushes the caliper out and you cant bolt it on without the wheel jamming against the pads.
Yup - this is a problem with the old style Magura mounts. They have a 'leg' on the back that braces against the inside of the fork brace or seatstay. Works ok, but if the brace is on the small side (as the older Pace ones are) then it pushes the brakes in towards the rim.
Magura solve this problem with the new EVO II brake mounts. They brace against a metal booster that mounts behind the brakes, not the frame:
You could buy the EVO II mounting gear, and it should fit your older Magura HS33s, as the cylinders haven't changed in design or size in years, just the mounts.