Stale NFS file handle and Samab

I'm trying to connect a linux box to a win2k3 server share (with smb
signing turned off in the group policy)

The share appears to connect OK:
mount //xxx.xxx.xxx.xxx/c$ /mnt/c -o username=xxxxxx,password=xxxxxx

but entering the directory and doing an ls gives:
ls: .: Stale NFS file handle

also doing ls -l on the directory above gives permission denied:
[root@mail mnt]# ls -l
ls: c: Permission denied
total 4
drwxr-xr-x 2 root root 4096 Nov 25 2004 floppy
[root@mail mnt]# umount /mnt/c

Is this correct?

I can umount the directory OK and try remounting but it doesn't work.
I've also tried remounting in a different place, & restarting smb but
still always get this error.

Any ideas?

cheers,

mark