--- org-clock.el.week	2013-02-20 13:36:02.465813986 +0100
+++ org-clock.el	2013-03-04 09:28:49.436080295 +0100
@@ -2518,7 +2518,7 @@
 	 (step (cdr (assoc step0 '((day . 86400) (week . 604800)))))
 	 (stepskip0 (plist-get p1 :stepskip0))
 	 (block (plist-get p1 :block))
-	 cc range-text step-time)
+	 cc range-text step-time tsb)
     (when block
       (setq cc (org-clock-special-range block nil t)
 	    ts (car cc) te (nth 1 cc) range-text (nth 2 cc)))
@@ -2538,17 +2538,21 @@
      (te
       (setq te (org-float-time
 		(apply 'encode-time (org-parse-time-string te))))))
+    (setq tsb 
+	  (if (eq step0 'week) 
+	      (- ts (* 86400 (- (nth 6 (decode-time (seconds-to-time ts))) 1)))
+	    ts))
     (setq p1 (plist-put p1 :header ""))
     (setq p1 (plist-put p1 :step nil))
     (setq p1 (plist-put p1 :block nil))
-    (while (< ts te)
+    (while (< tsb te)
       (or (bolp) (insert "\n"))
       (setq p1 (plist-put p1 :tstart (format-time-string
 				      (org-time-stamp-format nil t)
-				      (seconds-to-time ts))))
+				      (seconds-to-time (max ts tsb)))))
       (setq p1 (plist-put p1 :tend (format-time-string
 				    (org-time-stamp-format nil t)
-				    (seconds-to-time (setq ts (+ ts step))))))
+				    (seconds-to-time (min te (setq tsb (+ tsb step)))))))
       (insert "\n" (if (eq step0 'day) "Daily report: "
 		     "Weekly report starting on: ")
 	      (plist-get p1 :tstart) "\n")