error in cart

I have a menu item at the top of the page that directs to the cart.

I also have the cart module on the left of the page. When I press the button that says "Proceed to Checkout" it shows

"Limit reached. You can't add the product:
Limit reached. You can't add the product:
The cart is empty"

or just

" The cart is empty"

Although the menu link shows items in the cart.

Also, nothing can be added to the cart. I add a product, it looks like it is being added as usual, but when I go to the menu link to the cart it is not there, and when I go to the module link to the cart the cart is completely empty.

On the back end, I don't see these items in the Cart area under Customers

The problem went away yesterday, but its back again.

The sight is ourhappyguests.com

I have just installed the latest version (because I was also having issues with the thumbnails).

As for the cart, right now if I try to add something, it shows the cart is empty.

I think that there is a delay. If I come back later then they might be in the cart.

But the cart on the left and the cart button on the top right don't always show the same thing.

it is turned off in joomla global config, is there another place to turn it off?

I added some products an hour ago, but they haven't shown up yet in the cart.

I'm re-installing the templates and the css, I'll see if that does the trick and will get back to you afterwards if there are still issues.