ext3 file system not releasing space

Hi all
i am facing a problem with ext3 file system
df -h is showing 19gb is used even if there is not a single file on the mount point

/dev/mapper/vg01-archive
55G 19G 33G 36% /archive_log

OS == Linux cdrsvr 2.6.9-55.ELsmp #1 SMP Fri Apr 20 17:03:35 EDT 2007 i686 i686 i386 GNU/Linux

No hidden files on file system!
unmounted the file system and remounted but the problem is still there
don't know where the space is being used
pls help

thanx/Ajay S

hm this is a common problem when an application still has a file open, you delete it, the space is released when the application closes the file

but you say you have unmounted the filesystem?

then every file on the fs must be closed first

try to fsck the unmounted filesystem,

fsck /archive_log

and post a du -k and ls -laR of the fs