When I run sudo apt-get update;sudo apt-get upgrade in Ubuntu 11.04, I get the exception below. VirtualBox is currently on '4.1.2'. I have installed apt-cacher-ng on this machine and install apt-get points locally.
W: Failed to fetch bzip2:/var/lib/apt/lists/partial/download.virtualbox.org_virtualbox_debian_dists_natty_contrib_binary-i386_Packages Hash Sum mismatch
praveensripati@MyMini:/etc/apt/apt.conf.d$ cat 01apt-cacher-ng-proxy
Acquire::http { Proxy "http://localhost:3142"; };
What could be the reason for this?