This is an issue reported at The YouTube video ID is invalid or the video was deleted that I forked here, as the issue seems to be server related rather than due to a module bug.

It seems that on some server setups drupal_http_request fails or is extremely slow. Please refer to #28 in that post for a partial solution:

Hope this helps to other users, when you got this problem with drupal_http_request or others like curl, the problem is the server, in case of SELinux the solution is execute as superuser:

setsebool httpd_can_network_connect=1

yet others still seem to experience the same problem.