Is it ever possible to start over?

Me and my ex-girlfriend have been broken up for over a month and a half. My main thing with her was that she was pretty cold all the time. Just all around un-attentive, and cold. I mean, she was warm enough for there to be a relationship, but in my eyes not to keep it going.
At one point, she even admitted that she knows that I give more in the relationship, but to her (being a psychology major) she believes that in any relationship, one person will give more than another.
So, anyways I broke up with her (cos screw that right) plenty of girls out there, I'm not one to beg anyone for their attention, but now she's coming around, inviting me out places, and telling me that she still loves me, still thinks about me, ect, ect.
In your opinion, does it ever work the second time around? I mean I care about this woman, but I'm not really digging the fact of putting myself in harm's way again. I'm a relator and I need all my concentration to keep my business up and running. What signs should I look for or should I just keep this platonic or maybe friends with benefits?
If your listening, help!