ls problem

Hi,
I'm quite sure this is a bug somewhere, but i'm not sure where. I am 
running:

Linux version 2.4.18-3 ([email protected]) (gcc version 2.96 
20000731 (Red Hat Linux 7.3 2.96-110)) #1 Thu Apr 18 07:37:53 EDT 2002

and I get vastly different results for different flags. the du command is 
similar to ls -s. ls -s and ls -al give similar results as below (exept , 
of course, in blocks) This is particularly bad since I really need to 
know the correct filesizes on these databases for archive/backup reasons. 
Based on the amount of data I know is there and based on the size of a tar 
file created from these the 462M value is likely the correct one. Any 
response would be most helpful!

Trent
------------------------------

note BckEnd.mdb :

[root@ae1 root]# ls -sh /disk1/database|more
total 180M
4.0k BckEnd.ldb
176M BckEnd.mdb
 20k Data Export.xls
1.4M xxx.mdb
2.0M xxxModule.doc
4.0k yyy.ldb
148k yyy.MDW

[root@ae1 root]# ls -alh /disk1/database|more
total 180M
drwxrwxr-x    2 administ administ     4.0k May  5 07:16 .
drwxrwxr-x   12 administ administ     4.0k Mar 18 17:02 ..
-rwxrw-r--    1 user1    administ     1.0k May  7 12:39 BckEnd.ldb
-rwxrw-r--    1 administ administ     462M May  7 13:27 BckEnd.mdb
-rwxrw-r--    1 user2    administ      18k Feb 24 23:27 Data Export.xls
-rwxrw-r--    1 user2    administ     1.4M Mar 26 10:08 xxx.mdb
-rwxrw-r--    1 user2    administ     2.0M Oct 16  2002 xxxModule.doc
-rwxrw-r--    1 user3    administ     1.0k May  7 11:51 yyy.ldb
-rwxrw-r--    1 administ administ     142k Apr 24 16:46 yyy.MDW