pos… No one is able to post any comments. :-(

Am not sure what is happening on my blog, no one is able to post any comments, how it can be resolved?

“Duplicate comment detected; it looks as though you’ve already said that!”

My Setup Details:

Version: 2.9.2
PHP Version: 5.2.8

@Active Plugins

[1] AddToAny: Share/Bookmark/Email Button (.9.9.4.8)

[2] Admin Favicon (1.4)

[3] Akismet (2.2.7)

[4] Author Categories (1.0)

[5] Author Spotlight (Widget) (1.2)

[6] Breadcrumb NavXT (3.4.1)

[7] CaPa Protect (0.5.6.2)

[8] cforms (10.5)

[9] Exec-PHP (4.9)

[10] Google XML Sitemaps (3.2.2)

[11] List Authors (1.2)

[12] Ozh' Who Sees Ads (2.0.2)

[13] Register Plus (3.5.1)

[14] Restore Post Id (1.2.0)

[15] Sidebar Login (2.2.9)

[16] Table of Contents Creator (1.6.1)

[17] Thesis OpenHook (2.2.5)

[18] TinyMCE Advanced (3.2.7)

[19] WassUp (1.7.2.1)

[20] WordPress Database Backup (2.2.2)

[21] WP SEO Tags (1.9.3)

Is there any known coflict with any of these plugins?

[Mod Note: Various links moderated.]