diff --git a/collects/scribble/latex-render.ss b/collects/scribble/latex-render.ss
index 7f772ff4..5c88ec23 100644
--- a/collects/scribble/latex-render.ss
+++ b/collects/scribble/latex-render.ss
@@ -374,6 +374,7 @@
                   (if (rendering-tt) (format "{\\hbox{\\texttt{~a}}}" c) c)]
                  [(#\~) "$\\sim$"]
                  [(#\{ #\} #\# #\% #\& #\$) (format "\\~a" c)]
+                 [(#\uA0) "~"]
                  [(#\uDF) "{\\ss}"]
                  [(#\u039A) "K"] ; kappa
                  [(#\u0391) "A"] ; alpha
diff --git a/collects/scribble/struct.ss b/collects/scribble/struct.ss
index 8dc62029..f1cefbd1 100644
--- a/collects/scribble/struct.ss
+++ b/collects/scribble/struct.ss
@@ -14,11 +14,12 @@
 
 (define (collect-put! ci key val)
   (let ([ht (collect-info-ht ci)])
-    (when (hash-ref ht key #f)
-      (fprintf (current-error-port)
-               "WARNING: collected information for key multiple times: ~e\n"
-               key))
-    (hash-set! ht key val)))
+    (let ([old-val (hash-ref ht key #f)])
+      (when old-val
+        (fprintf (current-error-port)
+                 "WARNING: collected information for key multiple times: ~e; values: ~e ~e\n"
+                 key old-val val))
+    (hash-set! ht key val))))
 
 (define (resolve-get/where part ri key)
   (let ([key (tag-key key ri)])