As StacyCat mentioned, the bars have glycerine in them, and that is known to stall some people. It stalls me. I don't "object" to them, I simply recommend against them
The single thing that disappoints me about the Atkins-machine is the product line they push. You don't need any of the products to successfully low-carb, but many people do eat the bars with no ill effects. I'm just not one of them. Try checking out the forums at
www.lowcarbfriends.com - especially the "Lobby".
Try a week or 2 without the bars, and see if that breaks your stall.