Well that's odd. I originally began to code this with Code::blocks, and then I migrated to Visual Studio 2005 w/out any service packs installed ( might be the reason? ). I tried to recompile the code once again in Code::blocks after the progress done with Visual Studio 2005 and compiles it flawlessly. Perhaps it is one of the Preprocessor flags included in the DEBUG mode, and I believe it is _HAS_ITERATOR_DEBUGGING.