More details: 1) These posts/WP-blogs that I´m not able to like while using Firefox, don´t have this WP-element: "You can also manage your Likes using the toolbar that appears at the top of your screen while logged into WordPress.com. When viewing an individual post (as opposed to the blog’s home page, for example), you’ll see a Like button up there, too, like this: (picture) " http://en.support.wordpress.com/likes/
2) I dont know if this is relevant, but those blogs don´t open in https format in Firefox, only in http.
So, this seems to be a browser issue. Are there any other suggestions I could try (like certain settings), or do you think this is an issue that can be solved only by Firefox?
PS. To my previous post: IE does accept https, I needed to choose "open only the elements that are safe" (or something like that in English, which is not my native language)