Likewise-open plug in to pam to authenticate Windows AD users on a linux box. pam-mount will mount shared drives at login time using the login credentials. There is no need for samba to do this, and no need to write down your username and password in a file.

1. Install pam-mount.
   sudo apt-get install libpam-mount
   sudo mkdir -p /media/shared_folder_name
2. Set up shared drives to mount:
   sudo gedit /etc/security/pam_mount.conf.xml
   <!-- Volume definitions -->
<!-- <volume fstype="cifs" server="server ip adress" user="*" path="to_shared_folder" mountpoint="shared_folder_name" /> -->
<volume fstype="cifs" server="192.168.140.00" user="*" path="felles" mountpoint="/media/server_felles" />
3. Make gdm automatically mount shared folders at login:
   sudo gedit /etc/pam.d/gdm
   At the bottom of the file, add the following:
   @include common-pammount

Reboot and log in again. The shared drive should be available.

Resources:
wiki.ubuntu.com