I am not sure if your thread has a typo but my phone is running 50.5.005. If that is not what you have, I wouldn't change it yet. My 5800 has suddenly started discharging its battery in a few hours even when I do not use it. There are a number of posts on forums about problems with this update so I would bide my time if I were you.
I complained and am currently waiting for deleivery of a new battery (under warranty) to see if that helps