tar corrupts archives with sparse files >4 GB. Testcase follows:

   % echo "hello" | dd of=x bs=1 seek=4G
   % ls -l x
   -rw-rw-r--  1 szaka szaka 4294967302 Mar  3 22:40 x
   % tar cSf x.tar x
   % ls -l x.tar
   -rw-rw-r--  1 szaka szaka      10240 Mar  3 22:40 x.tar
   % tar vtf x.tar
   -rw-rw-r-- szaka/szaka 4294967302 2005-03-03 22:40:07 x
   % tar xf x.tar   (same result by 'tar xSf x.tar')
   % ls -l x
   -rw-rw-r--  1 szaka szaka          6 Mar  3 22:40 x



The thread at http://lists.gnu.org/archive/html/bug-tar/2005-03/msg00004.html
has more details.

The fix below is already merged in current tar sources.

Index: src/sparse.c
--- tar-1.15.1/src/sparse.c     2004-09-06 14:30:57.000000000 +0300
+++ tar-1.15.1-n/src/sparse.c   2005-03-04 00:50:05.000000000 +0200
@@ -1,6 +1,6 @@
 /* Functions for dealing with sparse files
 
-   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
@@ -182,7 +182,7 @@ sparse_scan_file (struct tar_sparse_file
 {
   static char buffer[BLOCKSIZE];
   size_t count;
-  size_t offset = 0;
+  off_t offset = 0;
   struct sp_array sp = {0, 0};
 
   if (!lseek_or_error (file, 0, SEEK_SET))