I don't know what I did to my machine, every time I shut down, i receive

umount: /var device is busy

and then the machine will try 3 times and then hail all devices. How do i fix this and what cause it?

also, rcd (ximian red-carpet daemon) stopped working as well, I uninstall and reinstall it but it didn't seem to help, red-carpet tells me it can't connect to daemon, when I do service rcd restart, it will tell me it fails to kill rcd and rcd is running all time time (it's "fake" one I supposed) and the system will also fail shutting it down. I am running RH Enterprise AS 3.

Any help is appreaciated.

post your /etc/fstab

LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
LABEL=/home /home ext3 defaults 1 2
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
LABEL=/tmp /tmp ext3 defaults 1 2
LABEL=/var /var ext3 defaults 1 2
/dev/hda2 /windows vfat defaults 0 0
/dev/hda9 swap swap defaults 0 0

/dev/cdrom /mnt/cdrom udf,iso9660 noauto,owner,kudzu,ro 0 0
/dev/fd0 /mnt/floppy auto noauto,owner,kudzu 0 0

there is probably a file on there that is in use... make sure that there are no defunct processes or anything, and that all files are closed... (i'm not sure how you would do that exactly but I've seen programs that tell you which files are open) That could be used to nail down the problem...