Replying to Couple mm gap between binding and ski?!?

Right just got my skis mounted up at a local shop and I was having a look after I had got back home etc and I notice that on all there was a very small space between binding and ski. Mostly it was you could just see a sliver of light through.
However, on one toe piece the gap is probably almost 2 to 3mm. I have look px12 bindings and I can "tap" the toe plate (where there are no screws) up and down a bit, if that makes sense. The screwed area is solid on the ski but there is the bit which isn't which can be pushed down etc.
Basically is this ok or should I get the guy to redo the toe binding? Tried screwing it down more but it just doesn't want to go.