I have a Wordpress MU installation with WP Robot installed on the main site (but for some reason it isn't installed in MU-Plugins, maybe we just have to move the plugin there).
For some reason on the 31 sites in the MU installation, the plugin isn't working. I know though that it works after some Googling around for 'mu plugins wp robot' and similar keywords. I can help you find information to fix this if you want.
I have wordpress login and ftp info ready to start immediately.