PHP modifies fields containing the characters space, dot, open square bracket and others to be compatible with with the deprecated register_globals
you can find a lot of workarounds in the comments here:
PHP: Variables From External Sources
For Exampe (comment by POSTer):
<?php
//Function to fix up PHP's messing up POST input containing dots, etc.
function getRealPOST() {
$pairs = explode("&", file_get_contents("php://input"));
$vars = array();
foreach ($pairs as $pair) {
$nv = explode("=", $pair);
$name = urldecode($nv[0]);
$value = urldecode($nv[1]);
$vars[$name] = $value;
}
return $vars;
}
?>