I'm trying to open a remote directory of images and loop through them in php... but I get this:
Warning: opendir(http://site.com/uploads/images/0-4999/341/) [function.opendir]: failed to open dir: not implemented in /path/to/file.php on line 175
I assumed it might be related to php.ini, and confirmed the setting:

allow_url_fopen = On

I also confirmed that opendir works locally.

The source files are just plain images that are accessible in the browser.

Any ideas on the problem?