I think disqus is different. They have some kind of "share this comment on twitter" feature that will post to your timeline. While those kind of trust relationships make me leery, there is an inherent trust in that if they start spamming people's timelines with disqus promotions, people won't comment and websites won't use disqus.
I get notified by firefox when there is a newer version available. It is an option (selected by default I believe) in the advanced section of the Tools -> Options dialog. It will even warn you if updating will disable any of your add-ons. I think your version of firefox may just have gone well past its use by date.
Also, use the placeholder attribute of the textbox to say what the purpose of the textbox is. Am I entering an email, a username, a password?