I think I found it: allow_url_fopen was Off (I put it off because of a security problem) and I just spotted the place where PhpDig gets the page content, yes, you guess it: with:
$file_content = @file($uri);
in function phpdigTempFile (robot_functions)
See also:
http://www.phpdig.net/showthread.php...llow_url_fopen
Is there a checklist somewhere, with requirements for PhpDig to function correctly? Could you add some checks in the code of the next version?