Share your experience!
Have you tried updating your phone?
http://www.sonymobile.com/global-en/software/phones/xperia-v/
Try reinstalling the update using PC Companion on your PC
For Windows
http://www.sonymobile.com/global-en/tools/pc-companion/
For Mac
Hi I got the same problem, I bought my Xperia V just a week ago and since I tried using the record button at the camera application it showed me a "camara no disponible" message and then it closes.
I already have updated to the latest release and it's just the same.