Fresh install of RVM in Ubuntu isn't letting me install gems (zlib error)

Question

Ok, I just created a fresh Ubuntu 11.04 install on Windows 7 using VirtualBox (not sure if this matters or not but just an fyi)

listing my rubies I get:

aaron@aaron-VirtualBox:~$ rvm list

rvm rubies

=> ruby-1.9.2-p290 [ x86_64 ]

but then trying to install the rails gem I get this:

aaron@aaron-VirtualBox:~$ gem install rails
ERROR:  Loading command: install (LoadError)
    no such file to load -- zlib
ERROR:  While executing gem ... (NameError)
    uninitialized constant Gem::Commands::InstallCommand
aaron@aaron-VirtualBox:~$ 

What am I doing wrong?

Edit:
After doing what Dylan said my output (to prove those libraries are now installed):

aaron@aaron-VirtualBox:~$ sudo apt-get install build-essential bison openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev ncurses-dev
[sudo] password for aaron: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'libxslt1-dev' instead of 'libxslt-dev'
Note, selecting 'libncurses5-dev' instead of 'ncurses-dev'
autoconf is already the newest version.
bison is already the newest version.
build-essential is already the newest version.
git-core is already the newest version.
libc6-dev is already the newest version.
libncurses5-dev is already the newest version.
libreadline6 is already the newest version.
libreadline6-dev is already the newest version.
libsqlite3-0 is already the newest version.
libsqlite3-dev is already the newest version.
libssl-dev is already the newest version.
libxslt1-dev is already the newest version.
libyaml-dev is already the newest version.
openssl is already the newest version.
sqlite3 is already the newest version.
zlib1g is already the newest version.
zlib1g-dev is already the newest version.
curl is already the newest version.
libxml2-dev is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
aaron@aaron-VirtualBox:~$ gem install rails
ERROR:  Loading command: install (LoadError)
    no such file to load -- zlib
ERROR:  While executing gem ... (NameError)
    uninitialized constant Gem::Commands::InstallCommand
aaron@aaron-VirtualBox:~$

Answer 1

Run rvm notes and make sure to use apt-get to install the things RVM tells you to. It (something along the lines of zlib1g-devel will be one of them).

For Ubuntu, it should be something like this:

/usr/bin/apt-get install build-essential bison openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev ncurses-dev

You might have to recompile your 1.9.2 afterwards (not 100% sure of that).