installing modules

I created a module installer... It is raw. But it's a start. I learned some Joomla a few days ago, and They have a module installer that does all the work for you. So here is my Drupal version. Unfortunately I just started using Drupal yesterday so I can't give it all the bells and whistles yet.

This installer makes a few assumptions:
1. GZIP lib is installed on server.
2. All modules will be installed in sites/all/modules

The installer will upload the tar.gz to the directory and automatically unzip it.

Everything on my aegir 0.4 alpha 6 installation is running fine. I just have one issue. When i install modules into the hostmaster platform, i have no problems but if i try to install modules to other platforms using drush, i get this error. "Drush command could not be completed"

when i download to the hostmaster platform:

:~/hostmaster-0.4-alpha6$ drush dl acquia_prosper
Project acquia_prosper (6.x-1.0-beta4) downloaded to [success]
/var/aegir/hostmaster-0.4-alpha6/sites/all/themes/acquia_prosper.
:~/hostmaster-0.4-alpha6$ drush dl skinr fusion