Works fine on me. I'm using VC7.1 and boost 1.33.1 (beta). The output is: Test: --test arg import the specified OBJ file and save it to MDLM format Running the program in Purify I get one UMR ( Uninitialized Memory Read ) warning. May it be that you are using some compiler settings that make the program crash when there is such problem with reading uninitialized memory? In any event Vladimir should be able to figure out the problem. Here is what Purify spits out: [W] UMR: Uninitialized memory read in ?distance@Vconst_iterator@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@std@@YAHVconst_iterator@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@0@0@Z {1 occurrence} Reading 1 byte from 0x0013ec23 (1 byte at 0x0013ec23 uninitialized) Address 0x0013ec23 points into a thread's stack Address 0x0013ec23 is 225 bytes past the start of local variable 'Off' in ?distance@Vconst_iterator@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@std@@YAHVconst_iterator@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@0@0@Z Thread ID: 0x298 Error location ?distance@Vconst_iterator@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@std@@YAHVconst_iterator@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@0@0@Z [c:\program files\microsoft visual studio .net 2003\vc7\include\xutility.:489] boost::program_options::?A0xeaa31ea9::format_paragraph(basic_ostream<char,char_traits<char>::std>::std&,basic_string<char,char_traits<char>::std,allocator<char>::std>::std,UINT,UINT) [c:\boost\libs\program_options\src\options_description.cpp:387] { // is last_space within the second half ot the // current line => if (unsigned(distance(last_space, line_end)) < (line_length - indent) / 2) { line_end = last_space; boost::program_options::?A0xeaa31ea9::format_description(basic_ostream<char,char_traits<char>::std>::std&,basic_string<char,char_traits<char>::std,allocator<char>::std>::std const&,UINT,UINT) [c:\boost\libs\program_options\src\options_description.cpp:453] boost::program_options::?A0xeaa31ea9::format_one(basic_ostream<char,char_traits<char>::std>::std&,option_description::program_options::boost const&,UINT,UINT) [c:\boost\libs\program_options\src\options_description.cpp:489] boost::program_options::options_description::print(basic_ostream<char,char_traits<char>::std>::std&)const [c:\boost\libs\program_options\src\options_description.cpp:522] boost::program_options::<<(basic_ostream<char,char_traits<char>::std>::std&,options_description::program_options::boost const&) [c:\boost\libs\program_options\src\options_description.cpp:288] main [c:\cybermdx\test programs\iostreams\iostreams.cpp:22] mainCRTStartup [f:\vs70builds\3077\vc\crtbld\crt\src\crtexe.c:398] Regards, Christian