Error when clicking email validation link

Hey there, I just got the Business edition earlier today after being helped out with an earlier issue, and so that I could use custom fields. Quite powerful software here. However I'm having an error now with email validation. I found threads on the forums here pertaining to some people not having the emails sent... I DO get the emails sent however clicking on the link brings up some bare php code and does not activate the account on the site. It is just a plain white page and this is the code that shows:

<?php
// pageok
// managed by puppet - hostingcms02
header("Content-type: text/plain");

// Total size of directory
$totalSize = 0;

// List of files in cwd
$dir  = opendir('.');
while (($filename = readdir($dir)) ==! false) {
   $files[] = $filename;
}

// The results of filesize are cached, clear that cache
clearstatcache();

// Total file sizes
foreach ($files as $file) {
  // Add file to total size
  $totalSize += filesize($file);
}

echo "pageok\n\n";
echo "Directory Size: $totalSize\n\n";

?>