pin 1 stuck high?

I am having a problem with pin 1 on my USB arduino; this pin goes high as soon as I power up the board, before any of the other code starts executing, and stays there. I have turned off serial w/ the jumper, and pin 0 works fine, but pin 1 seems stuck high. I have double-checked that this is what’s happening, all my other components are fine. Any ideas?

I'm having this same issue -- are we making a simple mistake, or ...?

The code I'm running is pretty simple:

int i = 0;

void setup()
{
  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(13, OUTPUT);
}

void loop()
{
  i++;
  digitalWrite(0, i & 1);
  digitalWrite(1, i & 2);
  digitalWrite(2, i & 4);
  digitalWrite(3, i & 8);
  digitalWrite(13, i & 1);
  delay(500);
}

Turns out that adding the line

UCSRB = 0; // disable serial out to free up pins 0 and 1

to setup() does the trick.

I think they plan to add the UCRSB line or its equivalent to the Arduino core, making the serial pins available for normal I/O unless Serial.begin is explicitly called…
See Mellis’ commments here

Yes, this should be fixed in Arduino 0007.