I ran in to a few issues while trying to install Dell Openmanage on the latest version of Proxmox (3.0).
In order to get things working correctly on Proxmox 3.x, here are the steps that are required:
#gpg -a --export 1285491434D8786F | sudo apt-key add --
#sudo apt-get update
Once you get everything installed correctly you will be able to log in to the Openmanage web interface here:
https://<hostname or ip address>:1311
The first time you log in you should use the ‘root’ username and associated password.