I have investigated the problem a bit and can reproduce it on my localhost too:
The error i get is the following:
Quote from curl
47 - Maximum (20) redirects followed
The weird thing is that there seems to be no redirect for the scripts.
If i disable CURLOPT_FOLLOWLOCATION it works fine.
Sadly the followlocation is needed for one or two sites, and i have currently no idea what's wrong.
If you encounter this error when linking another site, please let me know.
Maybe there is a bug in curl.
Edit:
The problem is that the gecko servers sends 302 status codes redirecting to the same page.
If i access the same urls with firefox i get a 200.