GCC 3.3.1: basic_string<unsigned char> class member var: unresolved symbolsduring link

[Bruno dot Voigt at ic3s dot de]

I have a problem to successfully build an app with g++ (regardless wether 
on sol2.9,rh8,cygwin,mingw).
This problem exists with all gcc 3.x versions.
I can successfully build the same app with SUN CC 5.[345], intel icc 7.1 
for linux, MSVC71.

The app compiles but during the link invocation (via g++) I get:

Undefined                       first referenced
 symbol                             in file
std::char_traits<unsigned char>::assign(unsigned char&, unsigned char 
const&)smpp_ip.o
std::char_traits<unsigned char>::copy(unsigned char*, unsigned char 
const*, unsigned)smpp_ip.o
std::char_traits<unsigned char>::move(unsigned char*, unsigned char 
const*, unsigned)smpp_ip.o
ld: fatal: Symbol referencing errors. No output written to smpp
collect2: ld returned 1 exit status

The app differs from similar ones which can be succesfully build with gcc
by having some class member variables of the form

std::basic_string<unsigned char>        rx_buf_;

What can I do to provide/instantiate the missing char traits functions?
Any hints are appreciated.

TIA,
Bruno