--- common.js.orig	2009-01-13 10:44:41.707409950 -0600
+++ common.js	2009-01-13 10:45:07.667412734 -0600
@@ -156,10 +156,12 @@
 	t_tag_separator = document.getElementById('tag_separator').value;
 	t_tag_string = document.getElementById('tag_string');
 	t_tag_select = document.getElementById('tag_select');
-	if ( t_tag_string.value != '' ) {
-		t_tag_string.value = t_tag_string.value + t_tag_separator + p_string;
-	} else {
-		t_tag_string.value = t_tag_string.value + p_string;
+	if (p_string != '' && p_string != t_tag_select.options[0].text) {  /* ignore "Existing tags" */
+		if ( t_tag_string.value != '' ) {
+			t_tag_string.value = t_tag_string.value + t_tag_separator + p_string;
+		} else {
+			t_tag_string.value = t_tag_string.value + p_string;
+		}
 	}
 	t_tag_select.selectedIndex=0;
 }