function fetchHeader($url, $returntransfer)
{
	$ch = curl_init ($url);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, $returntransfer); 
	curl_setopt ($ch, CURLOPT_HEADER, 1);
	curl_setopt($ch, CURLOPT_NOBODY, 1);	
	curl_setopt($ch, CURLOPT_TIMEOUT, 10);
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);	
	curl_exec ($ch);
}

$arrTestUrl = array("www.alle-autos.ch", "www.alpendrifter.ch", "www.cam-schweiz.ch", "www.bwinfo.ch", "www.canonshop.ch", "www.bmparch.ch","www.jahaya.ch");
reset($arrTestUrl);
foreach($arrTestUrl as $currUrl)
	{ echo $currUrl . "<br>"; flush(); $currUrl = "http://" . $currUrl; fetchHeader($currUrl,0); }


Running the above script generates no error. In my case the script crashed when using fetchHeader($currUrl,1) instead of fetchHeader($currUrl,1), for every given url.

I am using the curl that comes with php 4.1.1 and php as a CGI executable.