have you try Factory reset ??... my friend kena on is .... after OTA screen sometime will flick if you touch the screen.. but once do factory reset the everything okay   

it happen to me too.
but its very rare, i think it happen 3 times so far, i had the phone for 2 months.

its shouldn't be normal.
i was assuming its a cm bug. since i'm using aosp custom rom.
not a big deal consider its very rare and doesnt do any real damage.

the first generation nexus 7 have this weird screen become washout after watching a video.
it also need a screen off and on to make it normal again during android 4.1. luckily in 4.2, it will automatically restore the contrast after few seconds.

S2 is 2-3yrs ago phone.... and with the pathetic 512mb ram if not mistaken , 4.1.2 is too much to let it handle alredi...LOL

The update is only 86.56mb only?

What updates is in it?

If at the edge of the phone is normal, else not normal. Mine got this before and successfully claimed the warranty. 

I thought it's normal to have four gap (that look like hairline crack) at each of the phone four corners.
Mine have those as well 

Sone users claimed before but you have to be vwry firm and solid when dealing with SC. Normally they will said no first. .

My wife's S3 Samsung cable started to give problem, it's just a month months old unit. Charging is taking forever these 2 days so I swap it with my old Blackberry cable and it's charging fine now. I googled and found out that this is nothing new, warranty may give us the same quality cable again...