Fixed it.
$data = base64_decode(str_replace(\' \', \'+\', $_GET[\'data\']));
for whatever reason, Php was converting the +\'s from the GET
Fixed it by using the following code.
$data = base64_decode(str_replace(' ', '+', $_GET['data']));
For whatever reason, PHP was converting the +'s from the GET variablesinto spaces.