--- loncom/xml/lontexconvert.pm	2008/01/29 11:18:06	1.86
+++ loncom/xml/lontexconvert.pm	2008/07/18 13:09:33	1.88
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.86 2008/01/29 11:18:06 foxr Exp $
+# $Id: lontexconvert.pm,v 1.88 2008/07/18 13:09:33 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -113,7 +113,8 @@ sub convert_real {
     # reasonably well to ⇔.  If we get many more of these,
     # we're going to need to have a translation sub.
     #
-    $xmlstring=~s/\\rightleftharpoons/\&\#8660;/g;
+    my $lrharpoon = pack("U", 0x21cc);
+    $xmlstring=~s/\\rightleftharpoons/$lrharpoon/g;
 
     &Apache::lonxml::end_alarm();
     return ($xmlstring,$errorstring);
@@ -218,7 +219,9 @@ sub jsMath_converted {
 
 sub tex_engine {
     if (exists($env{'form.texengine'})) {
-	return $env{'form.texengine'};
+	if ($env{'form.texengine'} ne '') {
+            return $env{'form.texengine'};
+        }
     }    
     if ($env{'request.course.id'}
 	&& exists($env{'course.'.$env{'request.course.id'}.'.texengine'})) {