Could you show the revised code producing this result?

And also use the printing debugging trick suggested by toolic ad the end of his post Re^3: IP address validation when IP is picked dynamically, i.e.:

    my($key, $parameter_value) = split("=", $line);
    print ">>>$parameter_value<<<\n";
[download]

because this will tell you, for example, if there is a trailing new line or space character at the end of your $parameter_value variable.

Update: Ooops, too late, toolic was much faster.