This was one of two changes between IDE 0.xx and 1.00 that bite people. The virtual function 'write' in the Print class that most packages use changed from returning void to returning a size_t (presumably the number of bytes written). The other is changing the include files WProgram.h and WConstants.h to arduino.h. So you might want to search around for a version of LiquidCrystal that is compatible with the IDE you are using.