Marketpress Location Tax cookie?

So I wanted to show my client how the base tax rate only applies to CA orders...

Opened up Safari...put in a CA address, at the paypal screen it shows the tax and shipping...which is what we want...

Then I wanted to show what happens if another state is entered...so I reset safari, cleared the cache, opened site, clicked add to cart and it displayed the shipping and tax before I entered anything in there...and when I went to checkout...all the previous stuff was there...

where does it store that info? thought it would be cleared when I did a Reset and cleared the cache?

Should add that once I put in the new non CA info...it started working. Just curious why the cache clear and reset didn't clear it out.

Cheers,