Assignment operator does not work for StructTypeInfo<OwnTypes>

I'm working with the types_test unit test and found a bug when assigning
objects of own data types.

To reproduce that bug please expand the
rtt/tests/types_test.cpp:BOOST_AUTO_TEST_CASE( testTypes):

- Types()->addType( new StructTypeInfo<AType,false>("astruct"));
- somewhere in string test:
"var astruct aVar\n" +
"var astruct bVar\n" +
"aVar.a = 42\n" +
"do test.assertMsg(aVar.a == 42, \"aVar.a != 42 assignement failed -
testTypes\")\n" +
"bVar = aVar\n" +
"do test.assertMsg(bVar.a == aVar.a, \"bVar.a != aVar.a assignement
failed - testTypes\")\n" +

The assignment of a complete AType will remain untouched. The second assertion will fail.
Any solutions? I'm using the orocos-toolchain 2.6