WP2.7.1 anonymous comments EXTREMELLY slow

Hello.

I have an issue with WP2.7.1 – comments, added by not registered users (including anonymous), are extremelly slow. The comments itself is added to database quickly but it takes up to 5 minutes for the page with comments to reload after ‘submit’ button is pressed.

I do not experience it with registered users. Nor there’re any clues in Apache logs.

You can experience issue by going to e.g.
http://www.southparkvideos.ru/c-nastupayushhim-novym-godom

and trying to leave a comment there.

Following plugins are installed:
All in One SEO Pack 1.4.6.15
Brian’s Threaded Comments 1.5.20
Exec-PHP 4.8
Executable PHP widget 1.1
Flash Video Player 2.0
Google Analytics for WordPress 2.7
Google XML Sitemaps 3.1.2
Less 1.1
NextGEN Gallery 1.0.2
RusToLat 0.3
Search Everything 4.7.8
WordPress Database Backup 2.2.2
Wordpress Download Monitor 2.2.1
Wordpress Gravatars 2.7.1
WP-Polls 2.21
WP-Polls Widget 2.21
WP-PostRatings 1.11
WP-reCAPTCHA 2.9.4

Database has about 200 posts and about 2500 comments.

Server itself is a dedicated physical. MySQL runs on same server with Apache.

Thank you.