Index: openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl,v
diff -u -r1.196 -r1.197
--- openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl	30 Oct 2008 22:54:59 -0000	1.196
+++ openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl	31 Oct 2008 09:24:39 -0000	1.197
@@ -1543,10 +1543,13 @@
 
     set title "Differences for [my set name]"
     set context [list $title]
+    
+    # try util::html diff if it is available and works
+    if {[catch {set content [::util::html_diff -old $html2 -new $html1 -show_old_p t]}]} {
+      # otherwise, fall back to proven text based diff
+      set content [::xowiki::html_diff $text2 $text1]
+    }
 
-    #set content [::util::html_diff -old $html2 -new $html1 -show_old_p t]
-    set content [::xowiki::html_diff $text2 $text1]
-
     ::xo::Page set_property doc title $title
     array set property_doc [::xo::Page get_property doc]
     set header_stuff [::xo::Page header_stuff]