Timeout Error, can anyone confirm?

I have had a timeout error whilst trying to program an Arduino Mega 2560 from a mac (OS X) can anyone confirm they have a similar issue on the same/different hardware?

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("!!!");
}

void loop() {
  // put your main code here, to run repeatedly: 
  
}

I forget the details but there's a problem with some Arduinos and/or bootloaders when you send three consecutive exclamation marks through the serial monitor. Try:

  Serial.println("!!")

Pete

Yep, no timeout on that statement, I didn't realise this was a known bug! I didn't see anything on it, spent at least half an hour wondering why my code wasn't working.