Question : Why do my drive mappings disappear?

I am running a Windows Server 2003 domain on a large 600+ workstation network.  Just recently I have been getting complaints from random users around the campus that when they log on in the morning all of their drive mappings are there and functional.  When they leave their workstations and come back some time later, some of their drive mappings are completely gone.

Here is some back information that might help.

1)  There is only one login script running and it maps the drives as persistent.
2)  There are no virus or spyware detected on the network.
3)  There have been no recent network infrastructure changes.
4)  The problem is not isolated to just one part of the campus. It's completely random.
5)  There is nothing in group policy that runs any sort of script after the login script.
6)  The login script is not calling any other script.
7)  DNS has been tested and is running fine.

I have noticed that a couple of the users that reported the issue had lost network connectivity at the time the issue was reported.  However, it is my understanding that even if network connectivity was lost, the drive letter would still be there being it was mapped as persistent.

If anyone has any ideas or has encountered this issue before, I would appreciate the help.

Answer : Why do my drive mappings disappear?

We had a problem at my work with the same issue.

We isolated it to one particular make of PC. For us it was Dell GX270 workstations. The NIC card on those devices just seemed to drop mapped drives from the domain login script.

This started happenign after we changed the switches from 100/Full Duplex to Auto/Auto and also changed the NIC cards to Auto/Auto. We did this to improve conectivity and reduce colisions that were causing some network slowdowns.

However with the GX270 NIC's we had to set the cards back to 100/Full rather than Auto/Auto. This causes them to run slightly slower as the switches in our Comm closets are set to Auto/Auto detect but it did resolve the connectivity issues and network drive dropping issues.

Hope that helps, let me know if you need any details on checking your network interface card speed and duplicity settings.