Older items not appearing in shopping cart?

I have recieved several complaints from customers trying to add items to their shopping cart and the item will not add. It simpy dissappears and will not go into the shopping cart. I tested this out myself, but on a newer item, and it added just fine. It seems that only older items - possibly before I upgraded? - are not able to be added to the shopping cart. How can I fix this??

To clarify: when placing older items into the cart, the cart only responds with "your shopping cart is empty" instead of adding the item. It will not add even if another item is already there.

If you'll provide an address where we can see this for ourselves, we might spot something.

I'm having a similar problem. However, none of the products are showing up in the cart. The cart is always empty.

Just to test, I tried installing the same databse files and site files on my localhost server and on a different remote server. The cart is working as it should on the other two servers. Just not this one:

http://gc.palomar.edu//judyzen/

First, you need to fix your configuration file in:
/includes/configure.php

as you should not have the double forward slashes in your links ...

Thanks. I didn't notice the double slashes. Fixing the config file worked. Now the cart is working, too.

here is one of the items that will not add to the cart:

http://www.omglia.com/Earrings/DanglyEarrings/JackSkellintonNightmareBeforeChristmasEarrings

I am losing so many sales and getting multiple emails about this, ugh! I don't know what do :(

Your SEO/rewrites are causing the problem ... turn them off and see if it fixes it ...

That worked! Thanks!!!

Now - is there any way I can get that same function back, but have it NOT break my shopping cart? I much preferred descriptive URLs.