Xthreads another error

[1master1]

I had installed the "xthreads thread description" plugin.
Later i tried to create new thread and didnt gave the thread name and description,
just filled the body and hit the preview button.

The error arised at that time saying
Fatal error: Call to undefined method stdClass::verify_subject() in /home/diken/public_html/forum/inc/xthreads/xt_updatehooks.php on line 435
Next, i'm unable to post it or preview it, even though i filled the thread name and description.

I refreshed the page and started posting freshly. Then it allowed me to post that thread.