I was suffering a similar problem, all the libreoffice documents were corrupted when saving to a samba share.
In /etc/fstab my share mounting instructions are:
//1xx.xx.x.xxx/<share_name_or_IP_address> /mnt/<foldername> cifs auto,iocharset=utf8,nobrl,username=<windows user name>,password=<windows network password>,_netdev,uid=<username>,gid=<group_id> 0 0
It's seems that the "nobrl" option do the magic
Juan