In the admin area some black arrows show up along with Garland theme arrows.

In the admin pages black arrows show up with the garland arrows in the CiviCRM Menu block. Please refer to the snapshot.

I removed below code from drupal/modules/system/system.css. That stopped showing black arrows but the menu items still remained shifted to the right. I think modying system.css for a particular theme will not be a good idea though.

li.expanded {
list-style-type: circle;
list-style-image: url(../../misc/menu-expanded.png);
padding: 0.2em 0.5em 0 0;
margin: 0;
}
li.collapsed {
list-style-type: disc;
list-style-image: url(../../misc/menu-collapsed.png);
padding: 0.2em 0.5em 0 0;
margin: 0;
}
li.leaf {
list-style-type: square;
list-style-image: url(../../misc/menu-leaf.png);
padding: 0.2em 0.5em 0 0;
margin: 0;
}