fedora8下用apt-get 出现如下错误，怎么办呢？好像是签名检查的问题

vectorspace1

[root@localhost rar]# apt-get -y install texlive-xetex
Reading Package Lists... Done
Building Dependency Tree... Done
The following extra packages will be installed:
   cpp (4.3.0-8)
   dvipdfmx (0-0.23.20080520cvs.fc10)
   evince (2.22.1.1-1.fc9)
   gcc (4.3.0-8)
   gcc-c++ (4.3.0-8)
   gcc-java (4.3.0-8)
   gimp (2.4.6-1.fc10)
   gimp-libs (2.4.6-1.fc10)
   glib2 (2.17.0-1.fc10)
   glib2-devel (2.17.0-1.fc10)
   glibc (2.8.90-5)
   glibc-common (2.8.90-5)
   glibc-devel (2.8.90-5)
   glibc-headers (2.8.90-5)
   kpathsea (2007-31.fc10)
   libgcc (4.3.0-8)
   libgcj (4.3.0-8)
   libgcj-devel (4.3.0-8)
   libgcj-src (4.3.0-8)
   libgomp (4.3.0-8)
   libspectre (0.2.0-2.fc9)
   libstdc++ (4.3.0-8)
   libstdc++-devel (4.3.0-8)
   poppler (0.8.1-1.fc10)
   poppler-glib (0.8.1-1.fc10)
   poppler-utils (0.8.1-1.fc10)
   teckit (2.5.1-1.fc10)
   texlive (2007-31.fc10)
   texlive-texmf (2007-21.fc10)
   texlive-texmf-dvips (2007-21.fc10)
   texlive-texmf-errata (2007-4.fc9)
   texlive-texmf-errata-dvips (2007-4.fc9)
   texlive-texmf-errata-fonts (2007-4.fc9)
   texlive-texmf-errata-xetex (2007-4.fc9)
   texlive-texmf-fonts (2007-21.fc10)
   texlive-texmf-xetex (2007-21.fc10)
   xdvipdfmx (0.4-3.fc9)
The following packages will be upgraded
   cpp (4.1.2-33 => 4.3.0-8)
   evince (2.20.1-1.fc8 => 2.22.1.1-1.fc9)
   gcc (4.1.2-33 => 4.3.0-8)
   gcc-c++ (4.1.2-33 => 4.3.0-8)
   gcc-java (4.1.2-33 => 4.3.0-8)
   gimp (2.4.0-0.rc3.2.fc8 => 2.4.6-1.fc10)
   gimp-libs (2.4.0-0.rc3.2.fc8 => 2.4.6-1.fc10)
   glib2 (2.14.6-1.fc8 => 2.17.0-1.fc10)
   glib2-devel (2.14.6-1.fc8 => 2.17.0-1.fc10)
   glibc (2.7-2 => 2.8.90-5)
   glibc-common (2.7-2 => 2.8.90-5)
   glibc-devel (2.7-2 => 2.8.90-5)
   glibc-headers (2.7-2 => 2.8.90-5)
   libgcc (4.1.2-33 => 4.3.0-8)
   libgcj (4.1.2-33 => 4.3.0-8)
   libgcj-devel (4.1.2-33 => 4.3.0-8)
   libgcj-src (4.1.2-33 => 4.3.0-8)
   libgomp (4.1.2-33 => 4.3.0-8)
   libstdc++ (4.1.2-33 => 4.3.0-8)
   libstdc++-devel (4.1.2-33 => 4.3.0-8)
   poppler (0.6.2-1.fc8 => 0.8.1-1.fc10)
   poppler-utils (0.6.2-1.fc8 => 0.8.1-1.fc10)
The following packages will be REPLACED:
   tetex (3.0-41.fc8)
   (by (3.0-41.fc8)
   texlive) ()
    (3.0-41.fc8)
   tetex-fonts (3.0-41.fc8)
   (by ()
   kpathsea, (3.0-41.fc8)
   texlive) (3.0-41.fc8)
The following NEW packages will be installed:
   dvipdfmx (0-0.23.20080520cvs.fc10)
   kpathsea (2007-31.fc10)
   libspectre (0.2.0-2.fc9)
   poppler-glib (0.8.1-1.fc10)
   teckit (2.5.1-1.fc10)
   texlive (2007-31.fc10)
   texlive-texmf (2007-21.fc10)
   texlive-texmf-dvips (2007-21.fc10)
   texlive-texmf-errata (2007-4.fc9)
   texlive-texmf-errata-dvips (2007-4.fc9)
   texlive-texmf-errata-fonts (2007-4.fc9)
   texlive-texmf-errata-xetex (2007-4.fc9)
   texlive-texmf-fonts (2007-21.fc10)
   texlive-texmf-xetex (2007-21.fc10)
   texlive-xetex (2007-31.fc10)
   xdvipdfmx (0.4-3.fc9)
22 upgraded, 16 newly installed, 2 replaced, 0 removed and 1217 not upgraded.
Need to get 0B/183MB of archives.
After unpacking 205MB disk space will be freed.
Checking GPG signatures...               ############################## [100%]
E: Unsigned /var/cache/apt/archives/glibc-devel-2.8.90-5.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/glibc-headers-2.8.90-5.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/glibc-2.8.90-5.i686.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/glibc-common-2.8.90-5.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/glib2-devel-2.17.0-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/glib2-2.17.0-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/texlive-texmf-2007-21.fc10.noarch.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/texlive-texmf-dvips-2007-21.fc10.noarch.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/texlive-texmf-fonts-2007-21.fc10.noarch.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/poppler-utils-0.8.1-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/gimp-libs-2.4.6-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/gimp-2.4.6-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/poppler-glib-0.8.1-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/poppler-0.8.1-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/kpathsea-2007-31.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/texlive-2007-31.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/dvipdfmx-0-0.23.20080520cvs.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/teckit-2.5.1-1.fc10.i386.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/texlive-texmf-xetex-2007-21.fc10.noarch.rpm: sha1 md5 OK
E: Unsigned /var/cache/apt/archives/texlive-xetex-2007-31.fc10.i386.rpm: sha1 md5 OK
E: Error(s) while checking package signatures:
20 unsigned package(s)
0 package(s) with unknown signatures
0 package(s) with illegal/corrupted signatures
                                         ############################## [100%]
Done.
E: Handler silently failed