Siemens 3568i (Or below) are affected of a sms vulnerability which can crash mobile phone.

We can send a preconstrued sms in PDU format which cause crash of phone and his turn off.
After we can't delete that sms.

For details:
http://www.xfocus.org/adv.php?id=3

At this url there is explanation, exploit and tool for delete incriminate sms.