diff --git a/checkin_notes b/checkin_notes
index 88477097f6..33982eea00 100755
--- a/checkin_notes
+++ b/checkin_notes
@@ -26812,3 +26812,15 @@ David  6 April 2005
             host_edit_form.php
     sched/
         handle_request.C
+
+David  6 April 2005
+    - Core client: deal correctly with HTTP servers that don't support
+        the Range: option.
+        Namely: if we issue an HTTP GET request with a Range option,
+        and the reply header is 200 OK (rather than 206 Partial Content)
+        then assume the server is sending us the whole file;
+        reset bytes_xfered and offset to zero,
+        and open the file in "wb" rather than "ab" mode.
+
+    client/
+        http.C,h
diff --git a/client/http.C b/client/http.C
index 4c7540a9f0..60b49a08a7 100644
--- a/client/http.C
+++ b/client/http.C
@@ -799,7 +799,16 @@ bool HTTP_OP_SET::poll(double) {
                 case HTTP_OP_GET:
                     htp->http_op_state = HTTP_STATE_REPLY_BODY;
 
-                    htp->file = boinc_fopen(htp->outfile, "ab");
+                    // if server doesn't support range request,
+                    // prepare to receive the entire file
+                    //
+                    if (htp->hrh.http_status == HTTP_STATUS_PARTIAL_CONTENT) {
+                        htp->file = boinc_fopen(htp->outfile, "ab");
+                    } else {
+                        htp->file = boinc_fopen(htp->outfile, "wb");
+                        htp->file_offset = 0;
+                        htp->bytes_xferred = 0;
+                    }
                     if (!htp->file) {
                         msg_printf(NULL, MSG_ERROR,
                             "HTTP_OP_SET::poll(): can't open output file %s\n",
diff --git a/client/http.h b/client/http.h
index 755e744cd2..4f22e1d759 100644
--- a/client/http.h
+++ b/client/http.h
@@ -28,6 +28,7 @@
 
 // official HTTP status codes
 #define HTTP_STATUS_OK              200
+#define HTTP_STATUS_PARTIAL_CONTENT 206
 #define HTTP_STATUS_RANGE_REQUEST_ERROR    416
 #define HTTP_STATUS_MOVED_PERM      301
 #define HTTP_STATUS_MOVED_TEMP      302