Sounds like a load of bull poo on her part. Like someone already mentioned, when chicks are pissed, the last thing they wanna do is sit around and brood over it. They want someone to blab on about it and get it off their chest. She might be seeing another guy and/or crushing on another guy. Either that or you're just on the "friend ladder", therefor she could give a damn about hanging out with you.
I posted this in O/T a couple of months back.
http://www.intellectualwhores.com/masterladder.html