sorry dint change the subject line..... <div class="gmail_quote"> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi guys, I have downloaded libmad-0.15.1b.tar.gz from <a href="ftp://ftp.mars.org/pub/mpeg/" target="_blank">ftp://ftp.mars.org/pub/mpeg/</a> then I execute ./configure --prefix=/usr It says>>>>> configure: error: C++ preprocessor "/lib/cpp" fails sanity check then i downloaded libmad-0.15.0b.tar.gz In this configure step was fine but after that when i did make it gives following error: cc1: error: unrecognized command line option "-fforce-mem" how can i get rid of this and install libmad on my ubuntu pc. thanks </blockquote></div>