'Serial' was not declared in this scope

I am using the Arduino 1.0 IDE. I have two tabs in the IDE for my XXX.ino file and a YYY.cpp file. Why is it that if I include Serial.begin(xxx) in my main XXX.ino file everything compiles correctly but if I include the same statement in the .cpp file I get the error: 'Serial' was not declared in this scope. What include file do I need to bring in the proper defination of class Serial, that is automatically being included in the .ino compilation but not in the .cpp compilation.

#include <Arduino.h>

I haven't messed with 1.0 much yet, is serial broken?

write (print, println) is now non-blocking (until the ring buffer is full). flush no longer dumps the receive buffer but instead blocks until all pending data has been transmitted. Some folks consider the changes "broken". I'm agnostic.

I like 1.0 for the IDE changes.

Osgeld:
I haven't messed with 1.0 much yet, is serial broken?

It is most definitely not broken. In fact, I think the improvements to serial handling are the best improvements to 1.0. Having async writ is huge!