Same problem for me. I have some galleries created. The first 2 looks ok, but the next 2 does not.
All files and folders under the /galleries folder are set to 755 permissions.
the admin_gallery/common/properties.php file is changed to
$GLOBALS['permissions'] = array(
'dir' => 0755,
'file' => 0755
I'm attaching some screenshots to illustrate my problem: