[kovidgoyal]

The next most likely explanantion is that the articles in question have a different structure than the others, so the keep_only_tags will have to be adjusten for them. Post a link to one of these articles, and I'll have a look.

EDIT: Actually, I just switched the recipe to use auto_cleanup, which resulted in only one blank article that I could see and that article had onlya picture and one line of text.