I can no longer block Facebook's intrusive 'feature' of showing others when you have read their message in Opera x64 12.16 on Win 7.
I have been using the standard filter (https://www.facebook.com/ajax/mercury/c ... status.php) for months successfully, and just recently realized that my messages started appearing as 'seen' again. The last message that I managed to open without calling FB's PHP file was about 10 days ago, after that the filter no longer blocks requests to the URL.
I have done no changes to the filter nor my browser setup, so it's a little bit puzzling. This issue is also specific to Opera: I also use ABP on Chrome (my secondary browser), where the block is working. I have tried uninstalling and reinstalling Opera (while keeping my preferences etc.), which did not resolve the issue. Any clues? Can anyone replicate the issue?