Chris Bourne has very kindly researched the source of the problem that some people are having with this blog and WordPress free sites generally. As he summarises “this is not a browser issue. It is a WordPress issue. It will affect people who have either a WordPress.com account or a gravatar account. WordPress.com now finds the cookies from these and forces a login requirement no matter what the security settings on your site. This is hugely unfriendly and potentially dangerous. For example, I can now, because I am logged in, add new posts without reference to you, and this might not be what you want at all.”
The WordPress team are receiving lots of complaints about this. As you can see here: http://en.forums.wordpress.com/topic/you-must-be-logged-in-to-comment?replies=327 The discussion gets quite heated, and some WordPress staff tried, sort of, to help.
But sadly, overall, WordPress don’t seem to be responding sympathetically, having closed the comment string on their site and suspended customer service for the time being for those like me who have the free version of WordPress. All this does not make me inclined to pay for the full version. Althugh many folk don’t report a problem, there is significantly less traffic on my blog since these changes took place. So I will keep going with WordPress for the time being, but unless they sort it out soon I will look elsewhere for a blog site. Any further ideas on the subject will be very welcome!
Roger Haydon Mitchell's Blog 
I was very irritated to have to sign in to my account to post on other blogs and it was even worse because I couldn’t understand what was going on. It was not simply just signing in I had to also change settings and to be honest I didn’t even realise I had a WordPress account. All very strange.
By: Joanna on April 5, 2012
at 5:47 pm
Joanna, let’s hope this doesn’t need to turn into a sub-blog for wordpress support, but in short if your avatar is registered at gravatar.com, then you have a wordpress.com registration whether you wanted it or not. They are the same thing. The same password applies to both. This is sneaky but not dangerous, they do it to up their claims for the number of users (which is why it is impossible to de-register from either of them).
It becomes a problem when they decide, as now, to use the cookies these registrations create to affect access procedures, in this case for making comments. At present this only affects blogs like Roger’s (and many millions of others) that are hosted at wordpress.com. Privately hosted sites like mine and Martin’s and many many millions of others should not be affected.
Although WordPress is an open-source community and it is and allways will be free to use, it is ‘owned’ by a company called Automattic, who have great influence over decisions like this which are essentially commercial.
By: guileshill on April 5, 2012
at 10:27 pm
well, I’m glad to know it wasn’t me even if I do have to log in to post my relief at the research outcomes. Thanks for all the effort. I am no longer baffled just mildly annoyed. c.
By: strawhouse1 on April 5, 2012
at 10:49 pm
Thanks Guileshill for the more complete explanation. It took me quite a while to find out that gravatar and wordpress were linked and that was what was causing the problem. Transparency is much needed in many areas and even open source software it would seem (I study development management hence the comment I suppose :))
By: joanna on April 9, 2012
at 7:19 pm
And it just goes to show that gravatars don’t really work, at least they don’t if you didn’t recognize me!
Chris
By: guileshill on April 11, 2012
at 10:22 am