Domain Accounts keep getting locked out when trying to map drives

Hello,
Im stumped/perplexed and above. I have users who are mapping drives using the net use command. Problem is it seems almost immediatly they are getting locked out of there computers. This has been going on everyday and it is driving me crazy. I have tried to update the settings for passwords but that did not help. The drives they are mapping to are Samba shares going back to a Unix system. Is there something specific I can change to stop the massive amounts of messages everyday to unlock accounts??? Thank You =)