I encountered this problem in 6.06 today. If you have set 'ls' as an alias with argument '--color' in /etc/profile or $HOME/profile, it will be triggered.
The root cause is that, the script /etc/gdm/Xsession will source /etc/profile and $HOME/.profile, then it use "ls $1" to read /etc/X11/Xsession.d, the ANSI color control characters in its output will cause the problem. Here's the fix: modify /etc/gdm/Xsession, change line 82 for F in $(ls $1); do to for F in $(/bin/ls $1); do -- gnome-session fails when "alias ls='ls --color'" in .profile https://launchpad.net/bugs/48876 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs