Hi zouq, >who can tell me the reason? Do this command: gdb --version If it doesn't say 6.3, then go here, download, compile, and use gdb-6.3: http://directory.fsf.org/GNU/gdb.html If it does say 6.3, then I'm not sure. Are you compiling using "-g", "-g3", "-ggdb", "-ggdb3", or something else? Check out "man gcc", and go to the "Options for Debugging Your Program or GCC" section. HTH, --Eljay
