I have got a problem with a Duemilanove board in that pin 4 is permanently LOW.
I haven't used it for a few years and as far as I know pin 4 used to work ok.
Any suggestions as to how I can troubleshoot this? It is not a programming issue as all the other pins when set to HIGH will light an LED ok(ish) - I say ish because pin2 when set LOW still gives 2.1v but when set HIGH gives the same 4.8V as the other pins. I don't know whether these are linked problems.
Any thoughts would be most welcome.