when i plug my usb drive (those little ones 512MB) everything is fine until i try to umount it...

adsl-71-152-35-150:/# umount /media/usb1
umount: /media/usb1: device is busy
umount: /media/usb1: device is busy

and the same thing happens with my cdrom, and i can't eject it...

adsl-71-152-35-150:/# umount /media/cdrom
umount: /media/cdrom0: device is busy
umount: /media/cdrom0: device is busy

here is a copy of my fstab file...?? any suggestions???
I am running Debian 2.6.15 on a DELL Inspiron 710m

# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
/dev/hda3 / reiserfs notail 0 1
/dev/hda2 /boot reiserfs notail 0 2
/dev/hda4 none swap sw 0 0
/dev/hdc /media/cdrom0 iso9660 ro,user,noauto 0 0
/dev/sda1 /media/usb1 vfat users 0 0

While this is completely useless to you, It also happens with my cdrom at least half the time. So does anyone have any ideas?

Not really sure wether this helps you:

Remember to leave the folder, the device is mounted to ( close all konquerer/nautilus or whatever windows )
If that's done, try using "fuser". It shows processes accessing a file, to finde out, if there is still something or someone using the device.

In my case it seems to happen most when in CL. before booting x ??? Usually it's something like a text file which I have opened, read, and closed, the only way to get the cd out again is to reboot.