Can't update QTY in shopping cart

For some reason, customers can't change the QTY in their shopping cart.

In the Cart, you can highlight the amount. Change it to something else. But when you click UPDATE it just comes back with previous amount. If you go back to the product page, and add another amount to the shopping cart, it will add the two amounts (existing amount plus the QTY you just entered) so that is working. You can delete the item from the shopping cart. So that is working. But you can't change the amount while you are in the cart.

Is this a a setup thing that I missed maybe?

I tried searching site to see if someone else had experienced it but couldn't find it.

Thanks

No there's no setting for this. It should just work. Do you have a link to your site?

Sure. Try this:
http://www.qualitydigest.com/store/index.php?main_page=product_info&cPath=4&products_id=4

I just randomly picked that product, but they all seem to do the same. I tried in both IE7 and FireFox just in case it was a browser thing.

Thanks

Similar problem here:

http://www.zen-cart.com/forum/showthread.php?t=88156

Try changing temporarily to the 'Classic' template, too.

Could be a template problem as stevesh suggests, and changing to classic and a quick switch to "classic" to see of the problem occurs there would be useful information.

It could also be a mod problem (sometimes not the mod itself, but how it's been installed). What add-in modules do you have installed?

thanks for the info. I will pass this info on to our site developer