My solution to the issue was this - and sorry for not posting this sooner! It took a while to resolve the issue and I had totally forgotten where I had posted in an attempt to get an answer! So thank you for your question.
Quite simply, the issue with my phone was hardware apparently. I went to a really useful Nokia Service Centre in Ripley (Derbyshire) and the guy there took the cover off the phone, cleaned out all the dust and (this was probably the crucial part) RECONNECTED THE CAMERA CONNECTION PROPERLY.
I was told that there is a connection from the camera to the main board in the phone. This had worked itself lose and so he pushed it back on a bit better. I think this with the cleaning and generally making sure everything was plugged in fixed the issue.
It kind of makes sense. All of my issues were based around the camera or accelerometer. These 2 things are linked as the accelerometer is used by the camera to detect orientation. So maybe by doing stuff inside the phone, cleaning and making sure everything was firmly attached, did something to the accelerometer too.
So if you get this error, take it to a service centre (if in warranty) and get them to clean the gizzards of the phone and check all connections are firm.
Hope this helps and provides you with the solution you need!