failures while installing or setting

When I install the plugin, I get the following message:

The plugin generated 3834 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.

When I go on the plugin page, I get the following Notices:
Notice: Undefined index: mode in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 29

Notice: Undefined index: ratingpage in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 30

Notice: Undefined index: id in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 31

Notice: Undefined index: user in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 32

Notice: Undefined index: rating in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 33

Notice: Undefined index: by in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 34

Notice: Undefined index: order in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 36

Notice: Undefined index: perpage in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 38

Notice: Undefined index: rating in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 125

Notice: Undefined index: rating in /home/kerlu/Downloads/wordpress/wp-content/plugins/wp-postratings/postratings-manager.php on line 199

http://wordpress.org/extend/plugins/wp-postratings/