The shell script in the workaround failed here. The awk command produced a \x5b that sed choked on. So, I tweaked the awk script to bracket its output as sed character classes; that let the script finish, but I wound up with a corrupt fglrx_drv.so and had to drop into recovery mode, uninstall fglrx, then boot in to low graphics mode and reinstall it.
However, the thread in http://ubuntuforums.org/archive/index.php/t-2074962.html led me to a workaround that did succeed. I grabbed the /etc/ati/control from a 12.10 install that was running on the same system, copied that to the 13.04 system, and the watermark is gone.
The shell script in the workaround failed here. The awk command produced a \x5b that sed choked on. So, I tweaked the awk script to bracket its output as sed character classes; that let the script finish, but I wound up with a corrupt fglrx_drv.so and had to drop into recovery mode, uninstall fglrx, then boot in to low graphics mode and reinstall it.
However, the thread in http:// ubuntuforums. org/archive/ index.php/ t-2074962. html led me to a workaround that did succeed. I grabbed the /etc/ati/control from a 12.10 install that was running on the same system, copied that to the 13.04 system, and the watermark is gone.