      */
     protected function isImage (url :String) :Boolean
     {
+        if (url == null) {
+            return false;
+        }
+
         // look at the last 4 characters in the lowercased url
         switch (url.toLowerCase().slice(-4)) {
         case ".png":

            showNewMedia(url);
            didShowNewMedia();
        }
    }

    /**

import flash.system.Security;
import flash.system.SecurityDomain;

import flash.utils.ByteArray;

import com.threerings.util.Log;
import com.threerings.util.StringUtil;
