Xlock started with udev closes after 3 seconds

Question

Hi,
I want to start xlock when I pull my USB key out. It works far enough to see xlock for 3 seconds or even a minute but then it allways dies without comment
#cat /etc/udev/rules.d/50-unlock.rules
SUBSYSTEM=="usb", ACTION=="remove", ENV{ID_VENDOR_ID}=="foo", ENV{ID_SERIAL_SHORT}=="bar", RUN+="/root/bin/udevlock"
SUBSYSTEM=="usb", ACTION=="add", ENV{ID_VENDOR_ID}=="foo", ENV{ID_SERIAL_SHORT}=="bar", RUN+="/root/bin/udevunlock"
I tried various ways to start xlock some last about 3 seconds, some almost 1 minute but then xlock disappears
cat /root/bin/udevlock
#!/bin/sh
case 6 in
1)
/usr/bin/nohup /usr/bin/su -l mr -c 'DISPLAY=:0 xlock -mode pacman' # 3 sec
} </dev/null &>/dev/null &
2)
exec 0>&-
exec 1>&-
exec 2>&-
/usr/bin/nohup /usr/bin/su -l mr -c 'DISPLAY=:0 xlock -mode pacman' # 1 min
3)
/usr/bin/nohup /usr/bin/env -i 'PATH=/usr/bin' 'DISPLAY=:0' sudo -u mr xlock -mode pacman & # 3 sec
4)
/usr/bin/su -l mr -c 'DISPLAY=:0 xlock -mode pacman' & # holds 3 sec
5)
/usr/bin/nohup /usr/bin/su -l mr -c 'DISPLAY=:0 xlock -mode pacman' & # holds 3 sec
6)
( /usr/bin/su -l mr -c 'DISPLAY=:0 /usr/bin/xlock -mode pacman' & ) &> /dev/null # 3 secs
esac
instead of starting xlock i allso started a script that prints 1 number every 100ms to a tmp file, it also died after the same time.
Any good ideas?
Thanks

Answer 1

Ok, I could solve the problem myself by installing the latest nvidia driver. Now I guess the intel grahic card is not used anymore, but I don't really know...