I recommend upgrading to IDE v1.0.1, but if you insist on using v0023, you need to open this file
arduino-0023/hardware/arduino/cores/arduino/wiring.h
and comment out the round macro. Change this
#define round(x) ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))
to this
// #define round(x) ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))