She is one of girl of naughty girl. Came to know later on. Have been engaged in cyber sex and masturbation with many guys. But she keeps on saying to me, she has changed and no more the same, but I saw in her YM conversation history she said the same thing to all the guys. Knowing fully well perhaps she is cheating me all the time, I can not stop falling for her. What to do. I have know her for last 5 months, and in these 5 months she has cheated all of them (roughly 7 guys). And for last 2 weeks she said she has stopped totally and changed, so hard to trust her.
I need advice what to do? Do I giver her another change ( she was caught doing this to me 2 times before) or simply move on. By the way she lives very far from my city and I can't meet her often only after a month or so. She is 37 now.

'she lives very far from my city and I can't meet her often only after a month or so'

For pity's sake, you can't have any expectations, seeing her so little. Find another woman closer to you, with whom you can have a real relationship, if you are going to act this way. You don't trust her, and yet are asking total strangers if you should trust her. What good will it do for us tell you to trust her? We don't know her; she isn't here.

So she is doing things on computer ? Is she doing it in real life ?
You know she is doing it, you either accept the fact she is doing it or you stop taking with her. Really your choice, there is not a third option