apt-get trying to remove manually installed packages

[James Robertson <j@mesrobertson.com>]

I am running Sid.

while doing a dist-upgrade apt-get wants to remove a number of packages that are manually installed.

One example is rxvt-unicode which I manually installed.  I have run "apt-get unmarkauto rxvt-unicode" to ensure it's set to manual but it keeps wanting to remove it during dist-upgrade.

How can I prevent apt from removing my manually installed packages?