--- loncom/xml/lonxml.pm	2008/09/20 01:17:58	1.484.2.1
+++ loncom/xml/lonxml.pm	2009/10/04 03:42:42	1.484.4.3
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # XML Parser Module 
 #
-# $Id: lonxml.pm,v 1.484.2.1 2008/09/20 01:17:58 raeburn Exp $
+# $Id: lonxml.pm,v 1.484.4.3 2009/10/04 03:42:42 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -658,6 +658,7 @@ sub setup_globals {
   $Apache::lonxml::request=$request;
   $errorcount=0;
   $warningcount=0;
+  $Apache::lonxml::internal_error=0;
   $Apache::lonxml::default_homework_loaded=0;
   $Apache::lonxml::usestyle=1;
   &init_counter();
@@ -1586,9 +1587,12 @@ FULLPAGE
       my $spelllink .=&Apache::lonhtmlcommon::spelllink('xmledit','filecont');
       my $textarea_events = &Apache::edit::element_change_detection();
       my $form_events     = &Apache::edit::form_change_detection();
-      my $htmlerror=&verify_html($filecontents);
-      if ($htmlerror) {
-         $htmlerror='<span class="LC_error">'.$htmlerror.'</span>';
+      my $htmlerror;
+      if ($filetype eq 'html') {
+          $htmlerror=&verify_html($filecontents);
+          if ($htmlerror) {
+              $htmlerror='<span class="LC_error">'.$htmlerror.'</span>';
+          }
       }
       my $editfooter=(<<ENDFOOTER);
 $initialize
@@ -1662,6 +1666,21 @@ sub handler {
 	$request->set_last_modified(&Apache::lonnet::metadata($request->uri,
 							      'lastrevisiondate'));
     }
+    # Embedded Flash movies (e.g., from Camtasia) served from https will not display in IE
+    #   if XML config file has expired from cache.
+    if ($ENV{'SERVER_PORT'} == 443) {
+        if ($request->uri =~ /\.xml$/) {
+            my ($httpbrowser,$clientbrowser) =
+                &Apache::loncommon::decode_user_agent($request);
+            if ($clientbrowser =~ /^explorer$/i) {
+                delete $request->headers_out->{'Cache-control'};
+                delete $request->headers_out->{'Pragma'};
+                my $expiration = time + 60;
+                my $date=strftime("%a, %d %b %Y %H:%M:%S GMT",gmtime($expiration));
+                $request->headers_out->set("Expires" => $date);
+            }
+        }
+    }
     $request->send_http_header;
     
     return OK if $request->header_only;
@@ -1828,6 +1847,8 @@ sub error {
 
     $errorcount++;
 
+    $Apache::lonxml::internal_error=1;
+
     if (defined($Apache::inputtags::part)) {
 	if ( @Apache::inputtags::response ) {
 	    push(@errors,