Mising items on adding in cart

[alexkaranda]

Issue: only the last item added in cart if you use product detail pages.
Magento version: 0.74.0-beta1

Steps to reproduce:

• install sample data
• open a women category page
• visit a product page from this category
• add product in cart
• open a man category page
• visit a product page from this category
• add product in cart

Expected result:
two items in cart
Actual result:
the only last item in the cart