I have the same problem (Application is still running close it and start the camera) from last Week onwards, i went to the sony ericson service station, they told some Part(board) to be replaced and It will take 15days hardly,I dint accepted his comments, Then i worked full fledged on this and i got the solutions,
*Remove the memory stick and push the air (from mouth)into the Inner camera.After that it will work Fine.
Reason: If Dust in your camera lens, the error will appear, so it is a matter of sensor.
* Observe the problem little closer, and fix it, b'coz you know your mobile very well than the 3rd Person.
Throughout all the mails regarding that error messages using Googles Search
Don't go Mobile service stations without knowing a nature error, because they ready to cheating us. Becareful.......... Freinds
Call me on my hand phone:
My Number: 9940097172
on Nov 25, 2014