Approximately half of all diabetic men will eventually develop erectile dysfunction [the inability to get or maintain an erection firm enough for intercourse]." That flat proclamation, from a doctor writing in a medical journal, is widely accepted by doctors and diabetics alike. But what many of the two million diabetic men who have erection problems don't know is that a significant number of them, particularly those under the age of 50, may be able to restore their sex lives simply by bringing their blood sugar back under control or by dealing with underlying psychological stresses.