I was surprised, when I strolled over to this blog to check for questions in the tag board, to see that trusty Firefox had blocked a pop-up.
Now, I hadn't installed any pop-up and I know blogger kinda hates pop-ups, so who could the culprit be?
I got a brainwave and went over to tag-board and deleted the latest spam comments in the tag board. Sure enough, no pop-up when I shut the blog page and opened it again.
So, if you have a tag board on your site / blog, make sure you delete spam posts regularly or you might turn visitors off.