diff --git a/buglist b/buglist
index f8e34a4..47f9b97 100644
--- a/buglist
+++ b/buglist
@@ -1,6 +1,6 @@
 =========================================================================
 
-bug 7248: 
+bug 7249: 
 todo 336:
 wish 1011:
 meh 5:
@@ -12,6 +12,39 @@ dup 50006:
 nonextend 60077:
 
 =========================================================================
+bug 7248: differentiation bug in D(1,z)
+
+(94) -> D(sin(z)^2+cos(z)^2, z)
+
+   (94)  0
+
+(98) -> D(simplify(sin(z)^2+cos(z)^2), z)
+
+   (98)  0
+
+
+BUT
+
+
+(95) -> D(1, z)
+
+   There are 5 exposed and 0 unexposed library operations named D
+      having 2 argument(s) but none was determined to be applicable.
+      Use HyperDoc Browse, or issue
+                                )display op D
+      to learn more about the available operations. Perhaps
+      package-calling the operation or using coercions on the arguments
+      will allow you to apply the operation.
+
+   Cannot find a definition or applicable library operation named D
+      with argument type(s)
+                               PositiveInteger
+                                 Variable z
+
+      Perhaps you should use "@" to indicate the required return type,
+      or "$" to specify which version of the function you need.
+
+=========================================================================
 bug 7142: exp^log(x) Cannot take first of an empty list
 
 WS> ElementaryFunctionCategory(): Category == with
diff --git a/changelog b/changelog
index b676600..cdfd7ae 100644
--- a/changelog
+++ b/changelog
@@ -1,3 +1,5 @@
+20140613 tpd src/axiom-website/patches.html 20140613.08.tpd.patch
+20140613 tpd bug 7248: differentiation bug in D(1,z)
 20140613 tpd src/axiom-website/patches.html 20140613.07.tpd.patch
 20140613 tpd buglist 7142 exp^log(x) Cannot take first of an empty list update
 20140613 tpd src/axiom-website/patches.html 20140613.06.tpd.patch
diff --git a/src/axiom-website/patches.html b/src/axiom-website/patches.html
index e905cde..5d7997f 100644
--- a/src/axiom-website/patches.html
+++ b/src/axiom-website/patches.html
@@ -4434,6 +4434,8 @@ buglist 7142 exp^log(x) Cannot take first of an empty list update
 buglist 7142 exp^log(x) Cannot take first of an empty list update
 <a href="patches/20140613.07.tpd.patch">20140613.07.tpd.patch</a>
 buglist 7142 exp^log(x) Cannot take first of an empty list update
+<a href="patches/20140613.08.tpd.patch">20140613.08.tpd.patch</a>
+bug 7248: differentiation bug in D(1,z)
  </body>
 </html>
 
