How can I fix too-crumbly shortbread?

Chances are there's an instruction somewhere telling you to chill it before rolling. But everything I learned about shortbread was that the ratio was 1 to 1 to 3 er to sugar to flour. Since you have two cups of er, you would have 2 cups of sugar and 6 cups of flour. Anyway, that's the recipe I use. You might go to allrecipes.com and see how many different ways they make it.