Name collision with 'nil'

ACE+TAO-1.5a
gcc3.4.4
linux

I'm trying to compile an app which pulls in some TAO code. However, I
get lots of name collisions on methods called 'nil' in TAO, e.g. the
following error is one of thousands just like it:

<blah blah>/ACE_wrappers/TAO/tao/Objref_VarOut_T.cpp:12: error:
expected unqualified-id before numeric constant

Here's the code it refers to:

10:    template <typename T>
11:    TAO_Objref_Var_T<T>::TAO_Objref_Var_T (void)
12:       : ptr_ (TAO::Objref_Traits<T>::nil ())
13:    {
14:    }

nil must be a #define'd constant somewhere or similar. Anybody know
where this collision is coming from and how this may be worked around?

Thanks,
Adam