The functionality of converting map options to smbmnt arguments is now
handled by /bin/mount.smbfs, which is shipped with Samba 2.0.6 or
later.  You therefore need to make sure you have /bin/mount.smbfs
installed on your system if you plan on using smbfs with autofs.

WARNING: Some versions of Samba incorrectly install this as
/bin/mount.smb rather than /bin/mount.smbfs.  If that is the case on
your system, please link or move /bin/mount.smb to /bin/mount.smbfs.
This is a Samba bug/misfeature and has been reported to the Samba
maintainers.