Bounce Rates and Premium/Free Plans

Hi there,

I downgraded from Premium to Free a few days ago.

The most noticeable thing has been the Bounce Rates. When i was in the Paid plan, it was always below 15%. Now i the free plan it went up to 70%... suddenly! For the same site, same traffic...

Why is that? The Premium plan offers a "better calculation"? If so, that's not a good idea.