Arduino v0022 Serial ERROR

I’m trying to compile the RepRap Firmware on Arduino v0022 and I’m getting the following error:

Serial_Error.cpp: In function ‘void setup()’:
Serial_Error:3: error: ‘Serial’ was not declared in this scope

On Arduino v0021 it works fine, I narrowed down the problem to the new HardwareSerial.h in Arduino v0022.

Example of the error:

#include <HardwareSerial.h>
void setup()
{
Serial.begin(9600);
}

void loop()
{
}

Anyone got an idea what is happening?

// What happens when you remove the following line…
#include <HardwareSerial.h>

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

void loop()
{
}