samba - Jul 2007 - multiple mounts for a smbfs on the same mount point

Hi all,
I'm just wondering why smbmount allows the same mount point to mount several
times the same share while a normal mount operation (with a non-smbfs) 
returns a busy mount point error.

[luca@fluca:~]$ mount
...
//server/sys on /mnt/target type smbfs (rw)
[luca@fluca:~]$ smbmount //server/sys /mnt/target/ -o ip=192.168.4.1,guest
[luca@fluca:~]$ mount
...
//server/sys on /mnt/target type smbfs (rw)
//server/sys on /mnt/target type smbfs (rw)

Any explaination? Is there a way to force smbmount to check about the current 
use of the mount point?

Thanks,
Luca