Comment 2 for bug 588518

Thank you for reporting this issue and taking the time to thoroughly examine the issue. On my fresh Xubuntu 10.04 installation, I show /usr/bin/gksudo as a symbolic link to /usr/bin/gksu. Further, I show the file /etc/alternatives/libgksu-gconf-defaults containing a single line:
    /aps/gksu/sudo-mode true
The way this appears to me is that gksudo and gksu are exactly the same command, and, include '--sudo-mode true' if no other system changes have been made.

Do you show the same symbolic link in /usr/bin ?