Preheat oven to 400°F.
In a saucepan, combine water, sugar, salt, corn syrup and lemon juice. Mix well.
Place over medium heat and bring to a boil. Remove from heat.
In a large bowl, combine cornstarch and water. Blend thoroughly.
Add frozen boysenberries to bowl. Stir to mix.
Pour contents of saucepan into bowl. Mix well.
Pour combined mixture into unbaked 9 inch pie crust. Cover with second top crust. Seal well around the edges. Make several slashes in the top to release steam.
Bake in preheated oven. Bake for 40 minutes, until top is golden brown. Remove from oven and cool on a rack before serving.