Biig problem with mount: cannot execute commands from a partition

[Andreas <andreas@www.debian.org>]

Hi!

I have a real big problem: Yesterday I have edited my /etc/fstab and since then, I cannot run commands from my /usr/ directory.

Here is my /etc/fstab:

 # /etc/fstab: static file system information.
 #
 # <file system> <mount point>   <type>  <options>                       <dump>  <pass>
 # /dev/hda4     /               ext2    rw,errors=remount-ro,exec,auto,noatime,sync     0       1
 /dev/hda4       /               ext2    rw,exec,auto,noatime,sync       0       1
 /dev/hda1       none            swap    sw                              0       0
 proc            /proc           proc    defaults                        0       0
 /dev/fd0        /floppy         auto    defaults,user,noauto,noexec     0       0
 /dev/cdrom      /cdrom          auto    defaults,ro,user,noauto,exec    0       0
 # /dev/hdb2     /usr            ext2    defaults,exec,user,noatime,sync         0       2
 /dev/hda2       /boot           ext2    rw,sync,noatime                 0       2
 /dev/hda3       /home           ext2    rw,noatime,sync                 0       2
 /dev/burner     /burner         auto    defaults,ro,user,noauto,exec    0       0


And here is my current /etc/mtab:
/dev/hda4 / ext2 rw,sync,noatime 0 0
proc /proc proc rw 0 0
devpts /dev/pts devpts rw,gid=5,mode=620 0 0
/dev/hda2 /boot ext2 rw,sync,noatime 0 0
/dev/hda3 /home ext2 rw,sync,noatime 0 0
automount(pid221) /var/autofs/misc autofs rw,fd=5,pgrp=221,minproto=2,maxproto=3 0 0
/dev/hdb2 /mnt ext2 rw,noexec,nosuid,nodev,sync,noatime 0 0


I have mounted /dev/hdb2 with the following command:
mount /dev/hdb2 -t ext2 -o defaults,exec,user,noatime,sync /mnt/

The partition seems to be clean (according to e2fsck -fc /dev/hdb2).

Has anybody suggestions what the problem is or what to do against it?

Thanx in advance


Andreas