php,获取json数据的错误

I have a webapp on my local server wich is currently using PHP 5.3.8. My webapp works perfect. Now I am testing the same code on our public host that uses PHP 5.3.3-7 + squeeze9 (no idea of what is squeeze).

The point here is that a simple get of some JSON data in the url doesn't work on the host.

I am using this:

http://webs.myapp.com/print.php?data=[%22O20130718ASDAS460600442%22]

At my local server I am able to get the info in data like this:

$info = json_decode($_GET['data']);   
$acompanantes = $info[0];

but I am not able to do the same on the other server. I know that if I update the host server php's to the 5.3.8 99% it will work, but I am afraid that the other things hosted there will stop working as soon as I update it.

Any idea on how should I try to get the data ?? What am I doing wrong ??

Thanks in advance.

PS: both servers use JSON version 1.2.1.