I have an Ubuntu 14.04x64 box in DigitalOcean. I installed everything by following Getting Started wiki page.
You can see the result of "dnvm list" command here:

When i run "dnvm use 1.0.0-beta4", i get the following error message:
Cannot find dnx-mono.1.0.0-beta4, do you need to run 'dnvm install 1.0.0-beta4'?
PS: Mono version is 4.0.1