My PCI ADSL modem stopped working on Thursday last week and I couldn't figure it out. Tried re-installing the drivers etc. and nothing. Raised a call with my ISP because I thought it was a BT line fault or something.
Eventually went and bought a replacement modem to see if it was the modem itself.
Guy in the shop says "ah.. fried modem? I've sold about 60 or 70 modems in since the thunderstorm on Thursday.".
Moral - get a surge protected for your ADSL line! It might just keep your £200 router safe.
cheers,
dave