Cookies have been a recognised security hazard for several years, for many security experts. Firefox Version 3 takes cookies very seriously, and expects you to do likewise.
Enable "Accept third-party cookies", and you'll do fine. Another case of excessive or mysterious security, and you should get used to it.
An Important Update
If you did not use a Blogger / Google account when you Followed this blog, years ago, you are probably not Following now . During the past...