Did you know that recent Government legislation changing the Freedom of information Acts gives you access to speed camera offences registered within the last twelve months and placed on a freely accessible website?
Every time your vehicle goes even over a mile or so over the speed limit, it is registered and placed on the database. They only send a ticket if you are way over, OR if you receive over 20 near misses!!!!!! You can now check how many you have against your vehicles' registration number.
http://www.i-database.co.uk/index1.php
I found it's worth checking the photo on the site to make sure it isn't a case of mistaken identity.