Compile problem with boost thread and function libraries.

Trying to compile the example at the bottom of the thread_group page (http://www.boost.org/libs/thread/doc/thread.html#example-thread_group), results in the following error for me: undefined reference to `boost::thread_group::create_thread(boost::function0<void, boost::empty_function_policy, boost::empty_function_mixin, allocator<boost::function_base> > const &)' (I also had to rename the variable count to something else because I was getting a "`int count' redeclared as different kind of symbol" error and change boost::mutex::lock to boost::mutex::scoped_lock.) I linked with -lboost_thread -lpthread -lstlport and am using Debian 3.0 with g++ 2.95.4, stlport 4.5.3, and boost 1.27. -jivera