/proc/mounts and /etc/mtab differs
 

Hi,
The mount points on /etc/mtab and /proc/mounts differs. Does it creates problem? sometimes the automount directory hangs. when I see the mount points under /etc/mtab and /proc/mounts the mount properties differ. When I try to shutdown the system hangs on nfs unmount. can anyone suggest a solution
Regards,
Satheesh