I am a woman, and I agree.
I said this in a previous thread...
"Past behavior is the best predictor of future behavior."
People usually don't change, and even if they do... It is damn hard to stay "on the wagon".
I got a couple of friends who "used to be whores". They have settled down into relationships now, but they still cheat occasionally and have feelings for ex lovers. (Their partners don't know this though)
Ask these questions...
"What is the longest period of time you have been single or went without sex?"
(The answer, although she may lie, and her reaction to the question will tell you a lot about her)
"What was her most serious relationship, and how did it end?"
(Critical. Again, she may lie...but pay attention to the reaction. Also, ask when's the lady time she talked to him)
Is she talking to you when she has a boyfriend? If so... She's just a cheater, or requires a lot of make attention. You alone will never be able to satisfy her. You aren't special. Don't think you can change her. You can't. (Even if she loves you to death.)