samba keeps disconnecting users
 

I have several users who need files off a samba server, they log on, and can connect then after two minutes or so the windows just close and then cant re-open them, it happens to windows 2000/XP workstations, if any user opens a file within an application it gets opened but then when they try to save it comes back and says machine name not found, and the user has to save locally.

users dont connect using mapped drives but instead use

\\<machine name or IP>\public\etc

i have had this problem since yesterday and is now becoming a major problem,

any help would be appreciated,

mattyG