diff -up mutt-1.5.21/imap/message.c.hdrcnt mutt-1.5.21/imap/message.c
--- mutt-1.5.21/imap/message.c.hdrcnt	2010-08-24 18:34:21.000000000 +0200
+++ mutt-1.5.21/imap/message.c	2011-04-01 15:23:14.254360560 +0200
@@ -65,7 +65,7 @@ int imap_read_headers (IMAP_DATA* idata,
   char *hdrreq = NULL;
   FILE *fp;
   char tempfile[_POSIX_PATH_MAX];
-  int msgno, idx;
+  int msgno, idx = msgbegin - 1;
   IMAP_HEADER h;
   IMAP_STATUS* status;
   int rc, mfhrc, oldmsgcount;
@@ -185,7 +185,7 @@ int imap_read_headers (IMAP_DATA* idata,
           continue;
         }
 
-        idx = h.sid - 1;
+        idx++;
         ctx->hdrs[idx] = imap_hcache_get (idata, h.data->uid);
         if (ctx->hdrs[idx])
         {
@@ -273,13 +273,14 @@ int imap_read_headers (IMAP_DATA* idata,
       {
         dprint (2, (debugfile, "msg_fetch_header: ignoring fetch response with no body\n"));
         mfhrc = -1;
+        msgend--;
         continue;
       }
 
       /* make sure we don't get remnants from older larger message headers */
       fputs ("\n\n", fp);
 
-      idx = h.sid - 1;
+      idx++;
       if (idx > msgend)
       {
         dprint (1, (debugfile, "imap_read_headers: skipping FETCH response for "