thanks for pointing it out...
this is a question for mellis: is it a backwards compatibility problem or is it that previous versions of arduino led us all to bad coding conventions?
A little of both. Arduino 0004 compiles sketches as C++ (whereas Arduino 0003 used C) which allows use to use the nice, Processing-like syntax for serial communication and other library. C++, however, is stricter about some things, like types and function prototypes. In general, though, it should be relatively easy to get things working. As usual, I'll try to help people who post in the forums, and summarize the main issues in the FAQ.