> XP changed the network layer once again and will apparently provide
> TCP/IP even without a network connection, but in all cases loss of a
> network cable can result in TCP/IP being switched off.

Which can be resolved by tweaking Windows:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
New entry into this folder
-Name: DisableDHCPMediaSense
-Type: REG_DWORD -Boolean
-Value: 0, 1 (False, True) Default: 0 (False), ----> 1 to switch it off Media Sensing

After setting this value, the machine must be rebooted.

Florian