@Noish
well try to repair via Sony PC companion if you can't find solution if its still there then it might be hardware.

@necr
Well you can always root your phone for custom rom for better performance i suggest over the weight of pros and cons ICS is better

@Norameen
Well,the font is big and the size of the palm is on the palm of your hand.
Personally for me,it is easier to read on my Xperia Go than my Xperia Acro S maybe because of the resolution.