Magento

We’ve run into a problem when attempting to checkout with more than 20 (configurable) products in the cart.  Basically, we can’t do it.  The store just hangs and then returns the user to the homepage.  Has anyone else had this problem?

I just tried adding 23 different types of (configurable) product in 4 different categories totalling 74 items to my cart and tried checkout, worked fine for me on my site.