compilation: exit() function

I'm having compilation problems with avifile on a RedHat 9 system with 
gcc 3.2.2. 

The 'configure' script fails to detect the Qt libraries.  The test 
program fails on this line:

   extern "C" void exit(int);

The error message is:
-----
     In file included from /usr/include/c++/3.2.2/cstdlib:52,
                 from /usr/include/c++/3.2.2/bits/stl_algobase.h:67,
                 from /usr/include/c++/3.2.2/memory:54,
                 from /usr/include/c++/3.2.2/string:48,
                 from /usr/local/qt/include/qstring.h:56,
                 from ctest.cpp:8:
     /usr/include/stdlib.h:612: declaration of `void exit(int) throw ()' 
throws
        different exceptions
     ctest.cpp:3: than previous declaration `void exit(int)'
-----

It works with the 'extern...' line commented out, but I don't know the 
overall effect of removing this.  Any ideas?