I just took a peak. if you look at line 129 in charon-merge/web/pluto-admin/operations/mediaBrowser/editMediaFile.php you will see this window opened with
<input type="button" class="button" name="moveFile" value="Move file to other directory" onClick="windowOpen(\'index.php?section=moveFile&fileID='.$fileID.'&filePath='.urlencode(stripslashes($rowFile['Path']).'/'.$rowFile['Filename']).'\',\'width=500,height=400,toolbars=true,scrollbars=true,resizable=1\');">
so it appears to be opened with both scrollbars, and being resizable (though I'm not sure if the resizable=1 should be resizable=true. You may want to look at whether changing the "true" to 1, or vice-versa.
I couldn't reproduce because I don't have many storage devices...