html image form: broken in 3.1.x with Pharo3

Image forms aren't rendered properly.

Forms are looking good in the image (aForm asMorph openInWorld shows a nice image).

But in html image form: aForm gives just little bits of black and white.

The /tools/screenshot exhibits the same issue, even in the OneClick image I downloaded a day ago.

That's really annoying. Anyone experiencing this?

Where to look?

Phil