SHOPPING CART WENT CRAZY! URGENT HELP NEEDED!!!!

Hi all,
We are experiencing quite a scary situation on our site and desperately need solution…quick! When a “guest user” adding items into the shopping cart, the shopping cart counter and price on the sub-menu are messed up. They don’t add up right. And when I click on the cart icon, it says my cart is empty. But It will still say I have something and price in my cart when I click on other categories in the nav menu. I can’t get to it and delete them because when I click it, it says I have nothing in my cart. Worst thing is that I can see these items in my other computer that is NOT logged on as admin or anyone, does that mean every visitors on the site can see items in their shopping cart!??! We need help urgently!!! Please visit hoveylee.com and check it out!

Any one having a similar issue?

Thanks,
Daniel