shared folder virtual box linux guest inside a host linux

The error in booting phase is "mounting local filesystems /sbin/mount.vboxsf mounting failed with the error no such device", but in fedora 12 dont stop despite fedora 10 do it, it show in login window a icon warning showing the message error in booting phase.

So the solution was to quit the line from /etc/fstab and put on /etc/rc.local. Show in images on next:

My Shared Folder:

My "fstab" file:

y rc.local file:

The link.