vnc server가 종료되는 현상

Fedora core1 사용중입니다.
왜 그런 지 모르겠는데
vnc server를 켜놓고 한참 있다가 보면 죽어있습니다.
연결을 몇번 해서 사용하고 다음날 접속해보려고 하면 죽어있거나 합니다.
vnc 로그 메시지를 보면 이렇습니다.

** (nautilus:26866): WARNING **: couldn't send tconX: res: ERRDOS - ERRnoaccess
The application 'gnome-panel' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
창 관리자 주의: 디스플레이 ':2.0'에 대한 연결을 잃었습니다;
아마도 X 서버가 종료되었거나 창 관리자가 종료/강제 종료
되었을 것입니다.
The application 'nautilus' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
The application 'rhn-applet' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
The application 'gnome-session' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
The application 'eggcups' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
Gdk-ERROR **: X connection to :2.0 broken (explicit kill or server shutdown).
The application 'pam-panel-icon' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
The application 'magicdev' lost its connection to the display :2.0;
most likely the X server was shut down or you killed/destroyed
the application.
xterm:  fatal IO error 32 (파이프가 깨어짐) or KillClient on X server ":2.0"