I've just discovered that Blogger are literally impossible to contact so I can't ask them what the problem is being caused by. They used to be contactable, I know because I did so back in 2006. This could violate my privacy, google/blogger is leaving a sign of which blogs I visit, now as it happens I don't visit (many) porn blogs, for example, but if I did stumble across one then the whole world would know as a banklink to this site appears.
Blogger's uselessness is hard to overstate, the provide a 'help group', where lots of other people who are experiencing the same problem can ask for help, but no one who can solve the problem is there. They also have a method of reporting a bug, but only from a preexisting menu of known bugs. So that is pretty much useless.
I realise that blogger is a free service, but even so their customer service is abysmal and it didn't used to be.
Update: Thinking about the problem some more.
- It affects some other bloggers, so the problem isn't unique there is unlikely to be caused by my own hardware and software.
- It has emerged recently so it isn't something wrong with the way that I configure my blog.
- It is only affecting a small number of bloggers, so much so that even on relatively popular sights my unintentional spam is often alone.
- Other bloggers are complaining about broken widgets.
- As the problem is unique to Blogger but not universal or even common among all users it might be the result of a broken widget.
- I shall try getting rid of most of my widgets, and disable banklinks on this site.