diff -ruNp curl-7.19.3.orig/lib/ftp.c curl-7.19.3/lib/ftp.c
--- curl-7.19.3.orig/lib/ftp.c	2009-02-11 10:57:33.334280000 +0100
+++ curl-7.19.3/lib/ftp.c	2009-02-11 10:59:43.957585266 +0100
@@ -3222,7 +3222,8 @@ static CURLcode ftp_done(struct connectd
       /* Note that we keep "use" set to TRUE since that (next) connection is
          still requested to use SSL */
     }
-    sclose(conn->sock[SECONDARYSOCKET]);
+    if(CURL_SOCKET_BAD != conn->sock[SECONDARYSOCKET])
+      sclose(conn->sock[SECONDARYSOCKET]);
 
     conn->sock[SECONDARYSOCKET] = CURL_SOCKET_BAD;
   }