I was thinking of writing this post only to see that I had already written it in 2009.
I find it fascinating how (in 1728) Franklin, were he serious, thought a cold deistic all powerful God created the universe but that the warm theistic deity he would worship was the God of our solar system, created by the ultimate unknowable God.
So maybe God the Father is actually a created being. That answers the "what caused Him?" question.