[Samba] can't write superblock

[nina]

Hi I have 2 servers. server 1(Fedora Core 2) shares /Shared with rwxrwx, 
server2(Redhat linux 9) mount to /Shared from server 1. When I did 
smbmount from server2, Shared is successfully mounted. I then remove 
/Shared and recreate /Shared from server 1, I started having problem 
from server 2. when I do mount, it still show Shared is mounted, but 
when I do ls -l / , it displays /Shared Input/Output error.
I can't unmount /Shared after that. When I try to umount,  it dislays 
can't write superblock. Can anybody tell me what's happening here? How 
can I fix it? If nothing I can do, reboot the system will umount  /Shared?