Supporter Plugin problem

I just installed my first mu plugin and I have big troubles. After I place the files on the mu-plugins folder with chmod 777 on it I've got just a blank page. After that I've turned the debug mode on and here are the results:

Notice: Undefined index: page in /var/www/wp-content/mu-plugins/supporter-ads.php on line 47 Notice: Undefined index: page in /var/www/wp-content/mu-plugins/supporter-framework.php on line 52 Fatal error: Cannot redeclare widget_supporters_init() (previously declared in /var/www/wp-content/mu-plugins/widget-supporter.php:41) in /var/www/wp-content/plugins/widget-supporter.php on line 209

Can anyone help me with this? The wordpress installation is 3.0 with multisite on.
Something that bothers me is the db-config.php supposedly on wp-contents folder where I should place some lines is not there and even creating that file and placing the lines on it still give me the same error.

Please help
Damian