What's up with comments not being posted timely or at all ?

Why does it take so long for written comments to showup ? I wrote a comment three times when I was already logged-in and each time I would try and submit, I had to re-log-in to submit, then it wouldn't submit the comment. I finally, edited my profile with new user-name and it accepted my comment, showed a preview of my comment to be posted 'shortly' and after two hours it still hasn't posted.