Syntax Highlighting Problem

[use.address@my.homepage.invalid (Chris Gordon-Smith)]

I am fairly new to emacs, and am having a problem with syntax highlighting 
with C++.

Although the highlighting seems to be working overall, it behaves strangely 
with macros. I have a trace utility that can log entry and exit to each 
function. To enable the utility for a function, I invoke a macro at the 
start of the function like this:

     TRACE

The odd thing is that the highlighting of the macro call is not consistent; 
sometimes it is in one colour, sometimes in another colour.

Can anyone help?

-- 
Chris Gordon-Smith
London
www.simsoup.info