Slideshow Gallery Pro broken again

Once again I’ve updated WordPress to the latest level and things have started going wrong. This time it’s slideshow-pro. It’s not showing anything at all. Earlier today, after a rather troublesome update to WordPress 3.1.1 (I’d rather not talk about it), the sexybookmarks plugin demonstrated a behaviour that I’d seen before. The fix was the same as previously noted; see How not to fix a problem with Slideshow Gallery Pro And then I noticed some more errant behaviour:

1. The [ slideshow] shortcode was not being expanded at all
2. When I installed the five-star-rating plugin I got a message saying Slideshow Gallery Pro was deactivated because it did not exist.
3. But I (re)activated it without getting the same message.
4. And now I just get a blank, where the slide show should have been.

So much for working through my TODO list!