"504 Gateway Timeout", "Proxy Error"

These are error messages that keep cropping up, and they both mean the same thing - a miscommunication between your browser and the page you're trying to access, probably caused by cookies in your browser. It happens you are using one of the links with "0-...brum.beds.ac.uk" in, which we use to present you to publisher sites as a University of Bedfordshire user. The only solution we've found is to clear the cache and cookies in your browser (how to do this varies depending which browser you are using) and start again.