Well I'm currently running this script on the latest version of XAMPP on a Windows 7 Pro 64-bit machine. I've also used it in XAMPP on my older Windows XP Pro 32-bit machine. No problems either way.
You may want to compare your server's configuration to the settings inside XAMPP (Apache and PHP settings). I've only tested this script inside of XAMPP.
I did have to enable the PHP cURL extension in the php.ini for the XAMPP installation, but I don't think that will solve your particular issue here.
Good luck with this. Sorry I can't help more -- but I am unable to reproduce the issue. If you figure out what the problem is, it would be great if you could report back here with a solution. Others with a similar server setup like your own would certainly benefit from it.