I've read most of the topics, related to pingbacks, but unfortunately didn't manage to solve my problem. It's similar to that solved problem - I have receiving of pingbacks working, but no sending working. I've installed WP-Crontrol and the only 2 WP-Cron entries in my queue are 'wp_update_plugins' and 'polls_crons'. I see nothing, related to the cant-send-pingbacks problem.
When I've installed the fresh installation of the forum 2 months ago, it's been working the correct way; only few changes later and I've lost the functionality. Unfortunately I'm not sure whether it is a problem in the theme or in any of the plugins - I have doubts of 'FCKEditor', 'HeadSpace2', 'Redirection', 'WP-CMS Post Control' and 'WP_Multilingual' plugins (if any of them is blocking the pingback functionality).
Any ideas of why I'm not able to send pingbacks or trackbacks?
Thanks in advance.