Thanks everyone - I think the packing is my problem. I've tried a bunch of different recipes and they all fall apart, so it makes sense that it's the packing. Even though the crust I made fell apart, the pie I tried this weekend was great:
graham cracker crust filled with 2 C fresh blueberries and topped with the topping from my favorite apple crisp recipe (1/2 C flour, 1/2 C sugar, 1/2 C oats, 1/3 C melted butter, cinnamon and 1/3 C sliced almonds). No one seemed to mind that the crust fell apart!