The user can remove his products from the cart. You will get the animation and it will be removed from it. However when the User clicks on links in my webshop the removed product will apear again. It won't show up in the checkout process and the cart will be empty. How can I fix this little bug that removed products apear again in the cart?
Comments moved to answer, so as to complete the question.
Potentially a cache issue. What version of magento? Are you using (3rd party) full page cache system?
If cache is the issue, you should check the cache configuration to not cache the checkout pages. Contact your cache extension developers for help.