PC -> DisplayDuino serial troubles

I’m connecting via serial usb to a displaydurino (atmega644p). I can serial from durino to PC just fine. When I serial from PC to durino through the serial monitor in Arduino the board freezes. if I close the serial monitor the board starts going again.

Anyone know why?

I’ve tried a variety of different drivers (running winxp atm) all to the same effect.

I’m running…

/* serial read/echo */
int incomingByte;

void setup() {
  Serial.begin(9600);
  Serial.println("READY");
}

void loop() {
  if( Serial.available() > 0 ) {
    Serial.print("I received: ");
    //while
    if((incomingByte = Serial.read())!=-1) {
      Serial.print(incomingByte, DEC);
    }
    Serial.println(".");
  }
}

Is this all of your code?

When I serial from PC to durino through the serial monitor in Arduino the board freezes.

The code you posted should echo the character it received. Perhaps that isn't working right. Without knowing whether anything gets echoed, or not, we can't tell.

What evidence do you have that the board "freezes"? What does that mean, anyway? Does it get real cold?

if I close the serial monitor the board starts going again.

Doing what? The code you posted does nothing but echo received data...

I have a version of the same code that blinks the on-board LED. when the serial window is open, everything is fine. when I send a message, the light stops blinking (sometimes freezing on, sometimes off). when i close the serial monitor the light start blinking again.