So I went to SamMobile.com and checked the list of firmwares available for:
Smartphone, Android, GT-I9100 Galaxy S II, Turkey and there was only one version of Android 4 which is 4.0.3:
I'm going to stick my neck out and say the best option is to flash the phone with the correct firmware. I'm going to stick my neck out and say that doing this will resolve your problems.
I'm not sure if SamMobile has every firmware out there but I'm sure they have nearly all of them.
Wait to see if someone else can shed some more light on the situation, I skipped the S2 so someone else may have more experience with S2 firmwares.