Pie Crusts

With any pie/tart crust if I feel there may be possible sogginess, I brush the shell with a mixture of egg white, sugar & water. I do this twice whilst blind baking and it produces a slightly crisp shell that holds up beautifully with any juicy or damp filling.

Try 1) blind baking the crust for 10 minutes or so before adding the filling and 2) warming the filling to about 130 F before adding it to the blind-baked crust. That way, the wet filling spends less time in contact with the crust before it fully cooks and sets.
This recipe uses the same idea, but it works with any filling: http://food52.com/recipes/15143_meta_givens_pumpkin_pie
Alternatively, you could eat the pie faster! A certain amount of sogginess WILL happen over time; not much you can do about that.

Do you pre-bake (ie "blind bake)the crust before filling it and baking it. It sounds like the crust may not be baked through.