Mega 2560 upload fail, solution for 1 case

I have noticed a very strange mega 2560 behavior and I want to ask if someone else has experienced the same. If I try to upload this code on arduino uno it will works perfectly

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println("ahhhh!!!");
}

When I try to put the same on an arduino mega 2560 the uploading process will never end, it crash!
Now try to remove the 3 !!!, the code will become

Serial.println("ahhhh");

and the uploading will be successfully accomplished.
So, I don't know if it's only with my board but I get the conclusion my mega cannot accept string containing 3 (or more) character of exclamation point!!! :astonished:

You have been bitten by the "unsearchable bug".

It's a bug in the 2560 bootloader. I believe a fix is available.

Read this post
http://arduino.cc/forum/index.php/topic,56926.0.html

It is a confirmed bug

you must upgrade the firmware