highlighting failure in a situation where macros are used within an argument list of function prototypes. The appended screenshot shows the highlighting result in Qt Creator 2.4.0rc of the following code snippet:
//----------------------------------------
#include <QtCore>
#define OWN //memory owned and managed from here
#define EXT //memory just referenced here, managed elsewhere
#define PTR(typ,mode) typ*

//func0: highlighted as expected:
void func0(QObject* a_parent,QString a_name);

//func1: highlighting fails on BOTH args, not just the one with the macro
void func1(PTR(QObject,EXT) a_parent,QString a_name);

//func2: argument order changed, highlighted as expected
void func2(QString a_name,PTR(QObject,EXT) a_parent);