So I tried to get the MonoDevelop release in Subversion to work with Ubuntu Hardy Heron (8.04.1) and had a heck of a time getting it to work.

Finally after much chatting on the IRC channel I did these steps;

1. Setup badgerports as a repository
2. Do the the 'ol 'sudo aptitude update && aptitude upgrade' 
3. Run this; 'sudo apt-get install build-essential mono-mcs mono-gmcs mon-devel libmono-dev lipango1.0-dev libgtk2.0-dev libgtksourceview2.0-cil libgecko2.0-cil monodoc libmono-system-runtime2.0-cil gettext'
4. Ensure you have 1.9 mono-gmcs installed; 'gmcs --version'
5. Ensure you have 1.9 mono installed; 'mono --version'
6. Follow the Subversion setup on the Monodevelop website, all should work now

Enjoy!