Cart says $103.94, checkout says $781.25. Taxes?

[centralpark]

thanks for taking the time to read my post.

i'm new here, and new to osCommerce. however my store is built and almost ready to launch. it lives here:

http://www.centralpark.com/store/

 

my question is, when i add items to my cart and try to checkout, the amount shown in my cart is accurate but my checkout amount is up to 7 times higher. it appears that the taxes are being calculated incorrectly but i don't know how to fix it. can anyone help or tell me where to look? i have a screenshot of the situation here:

http://www.centralpark.com/store/checkout_taxes.jpg

 

thanks in advance for any help,

aric