Windows Server 2003 drops clients

We have been having an recurring issue. We have several clients, some are logged in through a desktop, some through wireless on a laptop, and others are logged in using RDP. They are all accessing an EMR located on the server, and they are finding themselves dropped off the network on a regular basis. It won't log them off the workstation, but their program will quit, and they will have to start over. Sometimes the RDP clients will be kicked off.

We are seeing this warning and error quite often:

The browser service was unable to retrieve a list of servers from the browser master \\CGC-WCWH3 on the network \Device\NetBT_Tcpip_{74C1AD19-3D0B-48AE-AA7A-76C6EDE5F4F7}.
 
 Browser master: \\CGC-WCWH3
 Network: \Device\NetBT_Tcpip_{74C1AD19-3D0B-48AE-AA7A-76C6EDE5F4F7}
 
 This event may be caused by a temporary loss of network connectivity. If this message appears again, verify that the server is still connected to the network. The return code is in the Data text box.

and

The browser service has failed to retrieve the backup list too many times on transport \Device\NetBT_Tcpip_{74C1AD19-3D0B-48AE-AA7A-76C6EDE5F4F7}. The backup browser is stopping.


Any help as to what is happening and how to address it would be appreciated.

Thanks
Luke