Cancel registration in 'registration information fields' not canceling

One-sentence description

See title

Current behaviour

See title

Expected behaviour

Does cancel

Steps to reproduce

1. Try to register for an event that does have extra 'registration information fields', like the pub crawl.
2. After hitting the register button, a new page is loaded with the extra information fields.
3. Hit cancel.
4. You're still enrolled for the event :(