Hi, Because of network problem, what I had is a snapshot of CVS-HEAD-07-06-29-0909. If this bug is corrected/reported before, please ignore. in the file /boost/interprocess/mapped_region.hpp line 467, followed is a snip ============================================== //Check for fixed mapping error if(address && (m_base != (void*)address)){ error_info err = system_error_code(); this->priv_close(); // bug here throw interprocess_exception(err); } ============================================== because adjusting mapping address to page size granularity, which may cause m_extra_offset != 0. in mapped_region::priv_close::munmap will restore address with m_base and m_extra_offset. But at line 467, m_base did not be adjusted (it's adjusted at line 472), when priv_close() invoked, we got a wrong address to munmap. I think it affect windows version too (same file at line 309). one possible correction: move line 472~474 to 463 (*nix version). move line 314 to 305 (windows version). Best Regards, Wilbur Lang