0ms animations now takes a few seconds...

please explain. In the past, this is the way I've been told it should be done. How do I use "move" for that? 
And why is that not a bug? If I set a move it 0 sec, how come it take 3 sec? And it used to work, until last week

I was just giving you a workaround for now.  You can use the Move command to specify a location to move an element to and it should move it instantly.

Also, you can change it to 1MS and it works, so this is definitely not a bug (well, at least on the Mac it works, let me know if it doesn't work on Windows).

1ms doesn't work. It doesn't move at all...

Please try the enclosed app. I tested it in Windows and it works.

119 - Animation.zip

Ezra, what are you demonstrating with this example? There's only frame animation with movement, I never said it doesn't work.
the bug is even worse then I though. I can't concatenate a set of linear animations anymore (move object along a path). The element is stuck after the first movement.

Showing how 1MS moves an element to the designated spot, that's what you reported was not working in this ticket.

but there's only a single animation here, moving the butterfly from left to right in a few sec, althought set to 0ms

The app I sent you was set to move the butterfly in 1MS and it moves it instantly. At least that's what I thought I sent you :). Change it to 1MS it should work properly.  In the meantime we have another update coming very soon.