Thread: Getting undefined reference error from ZThread

Using MinGW 4.2.1, GCC 3.4.6.

ZThread compiles fine into a library but when i compile a class using it, I get the errors:

(ThreadLocalImpl.o):ThreadLocalImpl.cxx.text+0x8c):
undefined reference to `std::_Rb_tree_rebalance_for_erase(std::_Rb_tree_n ode_base*, std::_Rb_tree_node_base&)'

undefined reference to `std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'

undefined reference to `std::_Rb_tree_decrement(std::_Rb_tree_node_base*) '

undefined reference to `std::_Rb_tree_decrement(std::_Rb_tree_node_base*) '

undefined reference to `std::_Rb_tree_increment(std::_Rb_tree_node_base*) '

undefined reference to `std::_Rb_tree_increment(std::_Rb_tree_node_base const*)'

Do you have any idea what might be causing these?

Thank you for any help you can give me,

Don