Ah...Finally this thread is marching towards an end.
BTW, in Windows there will be an option to reconnect the drives after logon. For ex., if u map a drive in Windows, you have to check mark that option. Anything similar to that available in Linux??
Update: Got from technet forum.
This issue can be caused by firewall. I suggest that you temporary disable the firewall on the computer and check the result.
Another reason is that the drive will drop idle connections after a specified time-out period to prevent wasting resources on unused sessions. The connection can be re-established very quickly, if required.