مشکل با نصب remote در ابونتو

[rubi]

از آموزش زیر رفتم ولی نشدubuntu 9
http://www.webhostingtalk.ir/f14/5681/

در این قسمت ارور داد

apt-get install xorg kde vnc4server kde-i18n-fa iceweasel iceweasel-l10n-fa-ir ttf-farsiweb unzip unrar-free chkconfig -qqy --force-yes

Reading package lists... Done
Building dependency tree
Reading state information... Done
Package iceweasel is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package iceweasel has no installation candidate


چه کنم