APT problems with Linux Mint 12. Is archive.ubuntu.com down?

I am having trouble accessing the APT repository at archive.ubuntu.com, I found out that if I changed it to gb.archive.ubuntu.com I could access the repository again. This is very annoying though. You would expect to be able to access the repositories when ever you need to. But it works just fine when I use the fix I tried. I wish that Linux Mint had just one packages source and was not a mix of Mint and Ubuntu packages. That would make a lot of sense. Therefore, if the main repository was having problems you could just switch to a repository in Germany. And just like the Ubuntu distribution you could change your /etc/apt/sources.lst to point to the packages for the new release and then run sudo apt-get update && sudo apt-get dist-upgrade. That does work with Ubuntu. Not being able to upgrade Linux Mint in place is annoying. You can do that with OpenSuse as well. The zypper command may be used to install the required packages. The process is outlined here: http://www.securitronlinux.com/my-linux-tips-and-tricks-page-part-1/.