In fact this happeded weeks before, maybe after upgrading to xorg1.8, when typing in xterm, it left with each letter with an annoying vertical line. [see the image attached] I believe this has something to do with compiz-wm, if I switch to the other window and switch back, those lines gone, but still appear when new letters typed in. And if I switch to the default Metacity wm, nothing annoying any more. Any people encounter such problem? I switch to urxvt instead as the terminal this days. installed packages: [i686] *compiz-core 0.8.6-2 xorg-server 1.8.1-1 xterm 259-1* -- Arch Linuxer, Pythoner, Geek --> Blog: http://apt-blog.net