Update done & I found some good features.
First of all, browser is changed a lot. Tabbed browsing added.
In locked mode just press menu key then date & time will be displayed with swiping option to unlock the phone.
I am exploring mode and will let you all about the update soon.
Thanks KB for info. +1 REP from my side to you.
One more thing smiley support for sms & also attachment option added.
@KB What error you getting.
As per link provided by you, Nokia has released a new firmware update for devices Nokia 5228, 5230, 5233, 5235, 5236 and the 5238.
So may be your nokia 51XX is not in the list.
swiping function is for TouchPhone only.
The new v50.x.xxx firmware brings some major changes for 52XX series handsets.