Thanks for your help Neil,
The autodisconnect attribute in my registry was already set to 0xffffff.
I already changed that a few days ago and it had no effect.
When my drives disconnect, I cannot reconnect them back.. When Windows asks me for my username/password, it always says "invalid credentials" like if it was unable to reach the domain controller to validate my username/password.
So I must logoff completely and login again to make this work. It is impossible to reconnect my drives.
Do you think it can have something to do in the way our Primary Domain Controller is configured? Remember that everything works fine on Win2k workstations but not on WinXP workstations.
Best regards,
Alex