If you're going to forward a port for the Belkin (which is best) then you need to set up a static ip for your computer. Don't choose the same no. as the router uses! Choose another higher such as the last one ending with any no. higher. Also, if you're running LW on more than one computer on the network, then you'll need to also port forward for the other computer(s) using a different port number to the first computer. It will also need to have a static ip different to both the other computer & the router. So for the 2nd computer you might choose a port no. between 49152 - 65535 such as 64049.

BTW if there is a bios error, then it sounds like you may have a computer or device which also uses the same ip number or allocation on the bios (whatever device that might be.) It sounds like a clash of identities. Each device needs to have a separate identity. You may need to cancel your previous port forwarding instructions given to the router & re-do them.

eg: If you're using SCSI devices, each needs its own identity allocated to it, else it will clash with another device & cause major problems. I believe the same principle applies to USB, firewire, etc.