This is an issue with your sources.list file maybe?
In a terminal, "pico /etc/apt/sources.list" and make sure they match this:
Code:
deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali-dev main contrib non-free
deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali-dev main/debian-installer
deb-src http://http.kali.org/kali kali-dev main contrib non-free
deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali main contrib non-free
deb [arch=i386,amd64,armel,armhf] http://http.kali.org/kali kali main/debian-installer
deb-src http://http.kali.org/kali kali main contrib non-free
deb [arch=i386,amd64,armel,armhf] http://security.kali.org/kali-security kali/updates main contrib non-free
deb-src http://security.kali.org/kali-security kali/updates main contrib non-free
apt-get update && apt-get upgrade
http://wiki.debian.org/Derivatives/Census/Kali