I rode for years in a Passier All Purpose. The saddle was uncomfortable for
me but fit the horse. I'm now riding a Passier dressage model.
I never had your pad problem with the Passiers, but did with other saddles.
I find it important that the pad be larger enough than the saddle to have a
good 3 inches of pad sticking out in front. If the edge of the pad is too
close to the pommel, the pressure on the outside edge of the pad tends to
push it back. Try placing the pad farther forward. A Woolback with both the
Velcro fastener over the panels and the slot for the girth works fine for me.
No pad slipping at all. I don't like the fasteners that slip onto the
billets because the stitching where the straps are attached form a lump under
the pad.
Linda