this is what my ISP told me:
QUOTE
It is very important to release the IP address from PC1 before you attempt to swap the Cable Modem, as because PC2 is using a different NIC MAC address to PC1. When the modem attempts to "match" the two sets of details (the CM Mac address and the NIC MAC address) it will already see a lease assigned to your CM MAC address with a different NIC MAC address. The upshot of which is that you will be refused an IP lease and get a 169 IP address assigned.
so yeah i need to release the IP manually, so can anyone help with the script? the last resort will be for me to buy a wireless router and a wireless PCMCIA card for my friend (he's staying with us for a few months), but that'll set us back around £160