Can you answer this transsexual's dating dilemma?

How would you handle this ethical dilemma?

Jane is 30 years old, attractive and single. She was born “John”, a male, and began the process of sex-transition at the age of 18. The process was completed with surgery at the age of 21. The surgery and hormone therapy have been a complete success and it is physically impossible to tell that she used to be physically male. Her legal ID has been changed to female and she is legally entitled to marry a man.

Jane has recently been asked out by Dave, who does not know anything about her medical background. Should she tell him, and if so, when?

If she confesses on the first date there is a very high probability that the relationship will proceed no further. If she waits until love has developed then Dave may find that his love for Jane overrides her confession and he may stay with her anyway. On the other hand he may be upset that she did not tell him sooner, and she risks the possibility that he may even become violent or abusive.

Does it make a difference if you are Dave? If you are Jane?