Strange error message in event viewer

[RobertS]

I get every 30 minutes a strange warming/error message in my event viewer.
The error is caused by a scheduled PHP script what runs every 30 minutes, the strange thing is that the PHP script itself is correct and does not error at all.

This is the warming/error in the event viewer:

Source: W3SVC
Event ID: 1011

Description:
A process serving application pool 'mijnwebspace.com(domain)(pool)' suffered a fatal communication error with the World Wide Web Publishing Service. The process id was '26884'. The data field contains the error number.

The code which causes this error is:

  function webcheck($url)
  {
   $ch = curl_init();
   curl_setopt($ch, CURLOPT_URL,$url);
   curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
   curl_setopt($ch, CURLOPT_TIMEOUT, 4);
   $buf = curl_exec($ch);
   $checkdata1 = "placeholder";
   $checkdata2 = "hosting for this domain is not configured";
   $checkdata3 = "forbidden";
   if ((preg_match("/\b$checkdata1\b/", $buf)) || (preg_match("/\b$checkdata2\b/", $buf))  || (preg_match("/\b$checkdata3\b/", $buf)))
                                         {
                                         $nosite = 1; // if there is no website or default Plesk page
                                         } else {
                                                $nosite = 0;  // if a normal site is present
                                                }
   curl_close($ch);
   return $nosite;
  }

What can I do to remove this warming from the event list?