[Samba] samba 4.1.4 ms office files at times "access denied"

[Tadewos Alemneh]

It isalmost a year that I am trying to get a solution for samba 4 problem(configuring).I use Ubuntu12.04 server and installed samba 4.1.4. Samba is used as DC AC and fileserverat the same time.The Problemis users from windows 8 PCs, who have the full right to folders and files willget at times (not always) access denied error when the try to open 
their own Microsoftoffice files on the samba server through LAN. This error comes at least once in a week. This is only for MS Office.Please help
tadewos