wp_get_http hanging on HEAD request

Hi,
I’m using wp_get_http in a plugin to validate the existence of a submitted URL and I’ve noticed that the function hangs on certain URLs. Hangs as in no response back to the plugin, and I’ve waited for longer than the timeout.

I’ve tracked the issue down to the HEAD request that wp_get_http uses if not supplied with a filename in the arguments. The requests that hang works if I change the method to GET (pass in anything other than false to wp_get_http).

I don’t know what the problem is with the remote servers, but, whatever the problem, I can’t have my form just hang. People tend not to like that. Has anyone else had this problem, or have a solution, or is this just a limitation of the way wp_get_http is written?