I am running Ubuntu in a Virtual Box environment. I need to update the guest but get an error.

Requires installation of untrusted packages

The action would require the installation of packages from not authenticated sources.
<code>
apache2 apache2-mpm-prefork apache2-utils apache2.2-bin apache2.2-common apport apport-gtk apt apt-transport-https apt-utils ca-certificates cups cups-bsd cups-client cups-common cups-ppdc curl dpkg dpkg-dev evince evince-common firefox firefox-globalmenu firefox-gnome-support firefox-locale-en flashplugin-installer gimp gimp-data gir1.2-dbusmenu-glib-0.4 gvfs gvfs-backends gvfs-fuse libavcodec52 libavformat52 libavutil50 libcups2 libcupscgi1 libcupsdriver1 libcupsimage2 libcupsmime1 libcupsppdc1 libcurl3 libcurl3-gnutls libdbusmenu-glib3 libdbusmenu-gtk3 libdpkg-perl libevdocument3 libevview3 libgimp2.0 libgvfscommon0 libnss3 libnss3-1d libpostproc51 librsvg2-2 librsvg2-common libswscale0 linux-headers-2.6.38-11 linux-headers-2.6.38-11-generic linux-image-2.6.38-11-generic linux-libc-dev nvidia-common python-apport python-problem-report tzdata tzdata-java udisks unity unity-common
</code>

I am stationed in South Korea using and Ip address from the host country. Could that be an issue?