FYI: If you’re having problems posting comments on some people’s blogs (like I have been), and you’re using gmail and blogger, it might be because you’re not logged into your gmail account. Being logged into your google blog (blogger/blogspot) account is not the same as being logged into gmail when you’re posting on those sites. I hope this information helps others having similar problems.
2009 Jun 14 05:47 EDT: This still doesn't work using Firefox. I used Netscape (obsolete browser) and it did. I might try Google's new Browser to see if that works.
2009 Jun 15 18:00 EDT: I have problems when I try to post comments on google blogs where the page is set to: Comment Form Placement - Embedded below post. When the setting is Full page or Pop-up window, it works okay. I changed my blog site to use Full page.