K750i white screen

Randomly, twice or thrice a day My k750i phone swithces off and displays the white screen. I noticed this happens allways before I get a tesxt message "SMS" in my inbox.

I pull out the battery and place it back to start the phone and I see a unread message in my inbox.

Pls help.

Read here : XS++ 3.1 Guide-Flashing, Customizing, Recovering - Top Sony Forums and post the connection log.
You need to reflash your phone, your phone firmware is damaged somehow.