cannot post to personal blog

I am unable to post anything at all to my personal blog (though I successfully created a group, a blog for that group, and posting to that blog). Whatever I type, today when I submit I get this message: 

     ! blog : This post can’t be referenced.

On previous days I got the message that I was suspected of being spam, but when I typed in the “captcha” and clicked submit, I got the above message. Today it just skips that step. Can anyone help?