I have experienced problem with security update KB2887069. The update needs reboot and the installation halts at 12% during shutdown and after a long period the installation is interrupted to login screen.
My PC is a Windows7, ASUS P8Z68-VPRO/GEN3 and ASUS GTX560.
I also have a laptop ASUS N61J Windows7 with no problem with the same update.
I have read some problem indications on other forums about this update.