When you turn the adjustment screw is it smooth or does it go click?
The old bindings are the smooth ones, my friend went through like 3 pairs where the binding just wouldn't stay in one place, he would do a run and they would move 1cm or more on the ski.
Apparently the latest ones have a detented adjuster so they shouldn't slide around.
Just out of interest, they're not on Kung Fujas's with insert screws are they?
Yup, warranty. Ask your store to talk directly to K2/Marker, tell them you want the new ones that have the clicky adjustment screw.
Must have been some ooooold stock Schizos, they fixed that a couple of seasons ago.