Yeah, it's a bit odd. To me it just sounds like she wasn't ready/wasn't over her ex. Or maybe she was using that as an excuse why things weren't working between you?
An ex is an ex for a reason afterall, so it surely should be a good thing that things were different with you compared to her ex? (If that makes any sense at all?)
Unless she was the dumpee, and never wanted to lose her ex in the first place....