[Samba] Defunct shares won't go away

[Joel Hammer]

I have two shares currently mounted with smbmount (linux) from an XP
computer which has left my network permanently. Its hard drive crashed.
Those two shares are still there. Any attempt to access these shares, say
with cd into them or fuser or umount, just causes the xterm I am working in
to hang.
Is there a way to get rid of these shares without rebooting?
Thanks,
Joel