I had this problem too but solved following way. I think it is not a bug. Some how file mode has been changed.
So, to fix it you should do following. sudo chmod u+s /usr/X11R6/bin/xscreensaver That's it. Good luck. -- ━━━━━━……‥‥・・‥‥……━━━━━━ Хүндэтгэсэн А.Отгонбаяр Компаний веб хаяг: http://www.usi.mn
