apt-get install -f fail, please help

[eric <fsshl@centurytel.net>]

Dear linux users:

 I meet following origin Signature check failed .  problem
when I use apt-get install -f

Calling dpkg with the following arguments...
/usr/bin/dpkg --unpack 
/var/cache/apt/archives/gnome-libs-data_1.4.2-8_all.deb
Authenticating /var/cache/apt/archives/gnome-libs-data_1.4.2-8_all.deb ...
debsig: Origin Signature check failed. This deb might not be signed.

dpkg: error processing 
/var/cache/apt/archives/gnome-libs-data_1.4.2-8_all.deb (--unpack):
Verification on package 
/var/cache/apt/archives/gnome-libs-data_1.4.2-8_all.deb failed!
Errors were encountered while processing:
/var/cache/apt/archives/gnome-libs-data_1.4.2-8_all.deb
Sub-process /usr/bin/dpkg returned an error code (1)
E: Sub-process /usr/bin/dpkg returned an error code (1)


welcome any hints

highly apprecaite your time and help

Sincere Eric