I've got 2. I just swap them when the one that's being used breaks. I'm doing this once a week or so...

EDIT: A development in the story... While I'm waiting for a modem I decided to have a fiddle around with the router itself. I set up all the security including MAC address filtering (Just to dissuade the casual script kiddies). I set it up as a whitelist from my laptop with the first entry being my PSP (because it was the first thing to hand). Anyway, I then spent about an hour trying to work out why the config page had stopped working and why the router stopped responding to Ping requests.  I'm searching around the internet and was almost going to ask here when it clicked.

Because my PSP was the only item on the list it was the only thing allowed to access the network... So, some awkward typing later (Typing in a MAC address on the PSP's on screen keyboard takes ages) I'm back in business!

The dunce strikes back!