error using avatars on fresh install

Well since did not find something as this here my problem, on a totally fresh/up to date install of multisite :

There was an error uploading the file, please try again.
Warning: imagecopyresampled() expects parameter 2 to be resource, null given in /home/centaure/public_html/wp-content/plugins/avatars/avatars.php on line 634

Warning: imagecopyresampled() expects parameter 2 to be resource, null given in /home/centaure/public_html/wp-content/plugins/avatars/avatars.php on line 634

Warning: imagecopyresampled() expects parameter 2 to be resource, null given in /home/centaure/public_html/wp-content/plugins/avatars/avatars.php on line 634

Warning: imagecopyresampled() expects parameter 2 to be resource, null given in /home/centaure/public_html/wp-content/plugins/avatars/avatars.php on line 634

Warning: imagecopyresampled() expects parameter 2 to be resource, null given in /home/centaure/public_html/wp-content/plugins/avatars/avatars.php on line 634

Warning: unlink(/home/centaure/public_html/wp-content/uploads/avatars/user/c4c/) [function.unlink]: Is a directory in /home/centaure/public_html/wp-content/plugins/avatars/avatars.php on line 1170

Warning: Cannot modify header information - headers already sent by (output started at /home/centaure/public_html/wp-content/plugins/avatars/avatars.php:598) in /home/centaure/public_html/wp-includes/pluggable.php on line 897

huh ? Oo