User Avatar used in some places, but not all.

I am using the User Avatar plugin.

On my website, the comments section is using the local avatar, but in the side bar, in the “Comments” tab, it is pulling the Gravatar.

To get the Avatar, the comments section uses:
<?php echo get_avatar($comment,$size='60'); ?>

To get the Avatar, the “Comments” tab uses:
<?php echo get_avatar($comment, '50'); ?>

I cannot seem to figure out what’s wrong.

Any advice would be appreciated.