Manfrotto MHXpro 2-W Fluid Head problem?

[beyond the blue]

I have just returned the above fluid head as it was not fit for purpose. The problem was, even on the lowest friction settings the tilting of the head lifted the legs of my tripod off the ground. The guy in the shop said there was nothing wrong with it and that's how they are. I got him to put it on the heaviest tripod he had on display which was quite a large devil but it lifted the legs of that one as well. I can't believe that it couldn't be faulty but the salesman (London Camera Exchange) insisted it was ok. Does anyone on here have the same head?