captureScreenshotOnFailure not working, broken

captureScreenshotOnFailure not working, broken

I can't get these screenshots working for the life of me:
The directories exist
The test executes (and fails) as expected
I've read everything I can find:
http://www.devinzuczek.com/2011/08/taking-a-screenshot-with-phpunit-and-selenium-rc/
PHPUnit Selenium captureScreenshotOnFailure does not work?
lots of others
Should be pretty simple, but there's no error messages, nothing. Can
anyone shed some light?
class ScreenshotTest extends PHPUnit_Extensions_Selenium2TestCase {
protected $captureScreenshotOnFailure = TRUE;
protected $screenshotPath = 'C:\\';
protected $screenshotUrl = 'http://127.0.0.1/';
protected function setUp()
{
$this->setBrowser('firefox');
$this->setBrowserUrl('http://127.0.0.1/');
}
public function testTitle()
{
$this->url('http://127.0.0.1');
$this->assertEquals('foobarbaz', $this->title());
} }