I could not get the dir argument in the shortcode working so I tweaked the plugin with this
in: classes/dropbox.class.php
before the call to upload() I check to see if dest was set
if(!isset($_POST['dest'])){ $directory = "/"; }
else { $directory = $_POST['dest']; }
This seems to have fixed my issue. There may be something deeper going on OR I may be misusing the plugin.
Tx
John-