Is it a clean Magento installation? So, one without customizations to the theme (even if it's the RWD theme), no installed extensions, etc.?
And if you look at the source code of your cart, does the href of that button also shows the URL /paypal/express/button/1?
If this response was helpful to you, consider giving kudos to this post.
If this response solved your problem, click accept as solution to help others solve this
