Screwup

When Barack Obama realized that Tom Daschle, the man he had nominated for the job of health secretary, was in a delicate and finally unacceptable taxation situation, the president made a frank mea culpa: "I screwed up." It would be nice if other world leaders could be equally candid about their faulty choices.

Incidentally, I'm curious to know the etymology of the verb "to screw up", meaning to botch something. Am I right in thinking that this verb might be a colloquial metaphor with sexual connotations? I seem to recall that it was common, in Australia, to tell a fellow to "go and get screwed", evoking Woody Allen's delightful: "I told him to be fruitful and multiply, but not in those words." In that case, Obama's language might not be papally correct. Before making a judgment on that Byzantine question, we would need to hear it in Latin.