Can't install on mediatetemple GRID - please advise...

[PDE]

I used to be with dreamhost and use roundcube, but had to leave them because of all the downtime. I'm now using mediatemple's gridservice (GS), but have been unable to install roundcube. The instructions at http://paulstamatiou.com/ don't work for me the way they did when I was with dreamhost.

Can anybody point me to information/guides that would help me install with mediatemple?

Thanks! I appreciate it.