new file group permission of CIFS mount

After switching from smbfs mount, the dmask/dir_mode and fmask/file_mode no longer have an effect on the newly created files. It seems to use the system umask instead.

I need the group to have write permissions without changing the root umask on the system. Any ideas?

example fstab:

//192.168.1.23/drive /mountpoint cifs gid=users,file_mode=0660,dir_mode=0770,credentials=xxxx 0 0

existing files have 660; newly created files after mount will have 644. I need new files to have 660. smbfs did this; cifs does not. I do need to use CIFS.