apt-get doesn't want to install package because of a lack of space whereas there are still 10go free

I've posted this issue for this package but you need to know that it happens with a lot of other packages. Moreover,lots of application didn't start : the shape of the window is drawing but nothing inside appears, the whole system becomes hardly usable.

Thank you for your attention.

ProblemType: Package
DistroRelease: Ubuntu 10.10
Package: texlive-lang-french (not installed)
Uname: Linux 2.6.36-020636-generic x86_64
AptOrdering:
 texlive-lang-french: Install
 texlive-lang-french: Configure
Architecture: amd64
Date: Sun Mar 13 20:21:59 2011
ErrorMessage: le sous-processus dpkg-deb --control a retourné une erreur de sortie d'état 2
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release Candidate amd64 (20100928)
SourcePackage: texlive-lang
Title: package texlive-lang-french (not installed) failed to install/upgrade: le sous-processus dpkg-deb --control a retourné une erreur de sortie d'état 2