tar遇到的一个问题

Question

我用下面命令：
     find . -type f -size -1000*1000c|xargs tar -cvf 0307.tar

它提示出了好多下面的结果：
a ./report/result_bak/cr01/200303/cr01_gw02.20030318 1 Blocks
a ./report/result_bak/cr01/200303/cr01_gw02.20030319 1 Blocks
a ./report/result_bak/cr01/200303/cr01_gw02.20030320 1 Blocks
a ./main/lock.h 1 Blocks
a ./main/afiedt.buf 1 Blocks
a ./main/profile.ini 1 Blocks
a ./main/backup/mainfile.h.20030330 2 Blocks
a ./main/backup/mainfile.h.bak 2 Blocks
...............................

但是 tar -tvf 0307.tar的时候，就只有最后的几个文件：
blocksize = 40
-rwx------    16/200     148 Aug 12 21:45:23 2003 ./trans/recv_0809.ini
-rwx------    16/200     143 Apr  4 17:54:16 2003 ./trans/new_0809.ini
-rwx------    16/200      76 Apr  4 17:54:16 2003 ./trans/runlog/runlog_main_2003-02-21
-rw-------    16/200     888 Aug 12 21:46:59 2003 ./trans/runlog/runlog_main_2003-08-12
-rw-------    16/200     570 Apr  4 17:54:09 2003 ./.dbxhist
-rw-------    16/200     871 Aug  9 18:04:07 2003 ./insert_log/makefile.aix
-rw-------    16/200     102 Aug  9 21:17:42 2003 ./insert_log/alib.list
-rw-------    16/200     887 Aug 10 15:01:17 2003 ./insert_log/makefile.cpq
-rwx------    16/200      20 May 26 16:40:43 2003 ./collection/mk

请问是什么原因？
thks