For several times:
1) I install backtrack 5 on usb with universal usb installer
2) I do fix-splash and I delete files and cache.kcache plasma_the_volatile.kcache
2) I update the apt-get
3) I update metasploit
All is well until I poweroff and I reboot startx responds:

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No protocol spécifié
..
No protocol spécifié
..
Giving Up
Xinit Resource temporarily unavailable (errno 11): unable to connect to X server

waiting for X server to shut down ddxSigGiveUp: Closing log

xinit: Server error.
xauth: error in locking authority file / root / .Xauthority

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please a final solution to this bug, I'm fed up to reinstall

Cordialy