Fatal error on update function advagg_get_root_files_dir

the same comes up in the latest dev version

i am in the dev now and add the lines
+864 +865

    // Make sure the advagg_get_root_files_dir function is available.
  drupal_load('module', 'advagg');

i upped the file and call the update script. now i become this error
user warning: Duplicate column name 'filesize' query: ALTER TABLE pre_advagg_files ADD `filesize` INT NOT NULL DEFAULT 0 in ./includes/database.mysql-common.inc on line 306.
user warning: Duplicate key name 'filesize' query: ALTER TABLE pre_advagg_files ADD INDEX filesize (filesize) in ./includes/database.mysql-common.inc on line 442.

i run the update and see the msg above again and
The following queries were executed
advagg module
Update #6109

Failed: ALTER TABLE {advagg_files} ADD `filesize` INT NOT NULL DEFAULT 0
Failed: ALTER TABLE {advagg_files} ADD INDEX filesize (filesize)
Failed: Could not get the filezie for for: sites/all/modules/slider/css/slider.css.
Failed: Could not get the filezie for for: sites/all/modules/slider/js/jquery.localscroll-min.js.
Failed: Could not get the filezie for for: sites/all/modules/slider/js/jquery.scrollTo-min.js.
Failed: Could not get the filezie for for: sites/all/modules/slider/js/jquery.serialScroll-min.js.
Failed: Could not get the filezie for for: sites/all/modules/slider/js/slider.js.
Failed: Could not get the filezie for for: /sites/default/files/myscript.js.

some filesize added but this the failures