Problem: When checking out you sometimes see someone else's shopping basket - or even
someone else's details in the address entry.
Solution: If you are using shop integration, then you may have set the links to the
items or the shopping basket in your homepage. Systematically go through all the
links of the shop, and make sure that none of them contain a so-called session ID
(that's the long number in the URL that looks something like this: /sess/utn153bbaacccsd91asfg..).