It looks like the server is not happy with certain requests, don't know why, but here's a quick and dirty way to get that out of the title.
In the phpdigCleanHtml function of robot_functions.php find:
Code:
$title = trim($regs[1]);
And replace with something like the following:
Code:
$title = trim(str_replace("400 Bad Request","",$regs[1]));