Jayce, see the very first post in this thread. You have a botched install, exactly like the problem I was describing in the very first post. Ignore all of the other stuff in this thread, as it isn't related to the install.sh or virtualmin-base issues (and I probably ought to move it to a new thread or something...but this forum kinda sucks and so I'd probably break something if I moved it).

You need to run:

dpkg -e virtualmin-base
apt-get install virtualmin-base

Running install.sh again will not do anything useful (and will actually break stuff).