getting error when trying to use certain piece of code with the new firephp/developer companion

[Z]

so I just upgraded last night to FirePHP 1.0 / Developer companion, and everything seems fine except for the following code I have to test page generation time

function get_microtime($s) {
list($mt1, $mt2) = explode(' ', microtime());
return bcadd($mt1, $mt2, $s);
}
// Page Generation Time Function
function get_execution_time($s = 7) {
static $execution_start = null;
if ($execution_start === null) {
$execution_start = get_microtime($s);
return 0;
}
$gen_time = bcsub(get_microtime($s), $execution_start, $s);
echo $gen_time;
global $_FirePHP; $_FirePHP->label('Page Generation Time')->log($gen_time);
}
get_execution_time(); register_shutdown_function('get_execution_time');

trying to run my app with this code at the top of the bootstrap leads to the following errors in the developer companion window

http://gyazo.com/4112745d1fc59a823511f04af5b0aae2 

[Christoph Dorn]

Sorry for the late reply (was having internet access issues).

Can you put up a test page I can access? This looks like a problem
with the payload that is sent to the client. If you cannot put up a
test page I'll have to add a debug mode so we can see what is being
received.

Christoph