Hello Ivaylo, just sharing.
If I may suggest, I have installed this plugin to help with preventing spammers :
After installation, amongst this plugin's settings you will find "Other WP Options". When you access the page you will find a listing of plugin settings which are either autoload "no" or "yes". If you check the listing you may find some settings of plugins which you have deleted but which are still set to autoload "yes". With great care (I repeat with great care) you can set to autoload "no" any remnants of settings of earlier versions of tubepress that you may find in the listing.
This has worked great for me, and although I do have access to PHPMyAdmin to make changes to database settings, nowadays I prefer to make changes to autoload settings right from the WordPress admin panel. I am just saying what has been my experience. Please research further before you actually try it. The slightest mistake you make may cause a database error, so please be careful.
Great tip - thanks!Go to the full post