[Plugin: FeedWordPress] Warning: file_get_contents(http:)

Hi, syndication of non-wordpress-feeds displays following warning and don’t work:

Warning: file_get_contents(http:) [function.file-get-contents]: failed to open stream: No such file or directory in …/www/wp-includes/class-feed.php on line 97

What can be the problem ?

thx

http://wordpress.org/extend/plugins/feedwordpress/