I've just upgraded ICS 4.0.4 on my Xperia Neo.
And facebook app says it has to upgrade to 1.9.6 version because the default version that is on Xperia ICS is 1.8.3.
I did it, but the version is the same, It's too slow, and sometimes I can't comment photos or in timelines. It's horrible the default version! I tried to install Facebook 1.9.6 apk from other pages and it's the same problem. It says that my Xperia actually has version 1.9.6 but it doesn't.
*When I had Gingerbread, my Facebook 1.9.6 app was excellent! 
What can I do?
Thanks
In the first one it shows how I had it, in the second one is what I have today and it says that it's the same version!
It's very slow.
