I found I had to refresh the map after every adding/or editing a marker via the info window that pops up over the map. It would be great if it did this automatically.
changing browser.php line 175 from
<img src="<?php print $geobrowser_path; ?>/img/close.png" id="close_button" onClick="hidediv('info_window')"/>
to
<img src="<?php print $geobrowser_path; ?>/img/close.png" id="close_button" onClick="hidediv('info_window'); map_redraw();"/>
does this for me. Can we add this to the next release?