here's a quick cheat to remove it, and it leaves behind a wee bit of code that you can use if you want to add in another link into that space.
in includes/languages/english/extra_definitions/all_business
you should have a file called footer_menu_defines.php
at around line 23 look for this code here:
Define('ABOUT', '<li><a href="' . zen_href_link(FILENAME_ABOUT_US) . '">' . BOX_INFORMATION_ABOUT_US . '</a></li>');
change that line to this:
Define('ABOUT', '<li></li>');
that will remove the link and leave the li tags inplace, incase you want to add another link in.
really there should be some more code removed from other files to get rid of that link completely, but just leaving the empty li tags will work fine^^
