I'm getting the same error, but different line:
Notice: Undefined variable: txt in x:\\path\\to\\joomla\\administrator\\components\\com_sef\\sef.class.php(385) : eval()'d code on line 50
I'm getting this message on each and every page within the site in addition to the ARTIO JoomSEF component settings administrator page.
This is a completely clean Joomla 1.0.13 installation, no other components, modules or mambots are installed, not even any extra templates.
Line 385 in the sef.class.php file is a long string starting with:
[size=4]eval(base64_decode('JHNlZkRpckFkbWluID0gJEd......'));[/size]
Edit: I added this to line 385 and it fixed my problem:
Ofcourse, this moved the eval(...) line down.
