In 4 years of using propecia i never had any problems keeping my erections, my sexlife was better then ever, never slept with more girls in my entire life then in this range of years. On the begening i had sencibility on nipples and this dissepeared 100%, i tought it was a major brest enlargement, catastrophic thing but it turn out to be nothing at all. The sencibility went off at 100% after some time.
But i had to stop because of testicular pain and probably prostate pain after 4 years. But no problems until then.
I think you should not be affraid to take Propecia anyways. Keep using it and see. IF the pain goes very strong then stop, until then, fight to keep your hairs.
Peac3
NB: I saw Star trek Generations last weak end and i cryed when Kirk died. Man this is no way for Admiral Kirk to die, it was unfair.