Cannot change Add to Cart quantity from 1

Over the last few weeks customers have contacted us saying that they are having trounble with our store. There is no problem in adding several different products, but if you change the quantity from 1 to any other amount on a specific product page and press 'Add to Cart', only 1 is included. If you try to change the quantity on the shopping cart page, and press refresh it stays on 1. Our store is http://www.cadwyngifts.com/ Has any one else come across this issue and know of any solutions? Many thanks.

If this is only happening on a single product then would first look at all of the settings for that particular product, in particular compare the settings of that product against a product that is not having the issue. Then the next thing is to look at the product type being used. This can easily be seen on the catalog side by reviewing the url generated: index.php?main_page=product_info versus say index.php?main_page=document_product_info.

Having max values and there are a few other settings that can cause this result, I just don't remember which do/might lead to that situation. But again, if it is one product and not all, or if it is product in one category but not all, this is helpful information to eventually lead to a solution/the area causing the trouble.

If I go through All Products or Featured Products and add quantities greater than 1 I get the message that the quantity has been adjusted to what is in the cart.

If you search in the Admin for this Product:
'Mam' Marcasite Pendant - 517

what are the settings on it for:
Product Qty Minimum:
Product Qty Maximum:
Product Qty Unit:
Product Quantity: