mm, usually people say that when they are kinda seeing someone. like they aren't dating, they're not exactly single. they are just getting to know each other better to see how they will work as a couple. or that inbetween stage of just before they start going out.
Well this is what I see talking as, say some guy walks up to you and says hey you have a bf? You say no, but I am talking to someone right now.
This is how I break it down, you meet someone, then after the first date or so if your still interested in them you start talking to them as in on the phone, now keep in mind your still single so if you want to keep seeing other people you can, because your not with the person yet.
The next stage would be second date or so then I would call that dating, now don't confuse that with relationship, this is the stage right before you get into a relationship, for example the girl I was talking to has recently said we were dating so I'm going to go with her on that, it would make sense to say that dating and talking mean the same thing if it were a perfect world.
Ummm I'm sure that talking last meant that you were conversing with someone else.never thought it had another meaning lol. But, if it was said in a jealous sort of way, it could mean flirting or something along those lines. I think that's where you're coming from with that, correct me if I'm wrong =].