Hello,
I have 2 issues with K2 with joomla1.5.x.

1- re-captcha words do not appear in the comments form. 'Enter 2 words you see below' appears but the words do not appear. I have enabled the re-captcha for comments and in the advanced parameters - anti spam settings i have entered the public and private keys.
2- after submitting comments I get message {"_errors":[],"message":"Comment added! Refreshing page...","refresh":1} on a blank screen. I am not getting re-directed to the website.

Hi, I have the same issues, but with J!3.2.
Did you solve your problem?

@Jayashree` what K2 version do you use and which Joomla! 1.5

@Илья Лобов have you installed the K2 2.6.8 SVN version which is compatible with J!3.2.1? If you haven't please do.
Don't forget to backup first.