cronjob not woking with plugin prosociate?

Hi, i have the plugin Prosociate installed in worpress mu which is setup with pro sites.

The plugin in question is install on a sub-domain site with domain mapping. The plugin is enabled via site settings > plugin and so overrides premium plugins. (it is my own site on what will be a multi user setup)

The plugin requires a cronjob to be run to keep prices updated from amazon, i run it via crontab with

wget –delete-after

It does not work?

The plugin dev does not support WP MU yet, so no help there.

Any ideas how might get cron working fro this?