If you experience that you can create a file perfectly fine, but can't create a directory or folder through a SAMBA share, then try issueing these two commands on your SAMBA server.
>setsebool -P allow_smbd_anon_write=1
>chcon -t samba_share_t /var/www/html
It took a lot of searching to find these two commands, so hopefully this will resolve your issues faster.
Reference:
fedoraproject.org/wiki/SELinux/samb
...