viewtopic.php?f=3&t=10087&start=0&st=0&sk=t&sd=a
The problem was quickly fixed (thanks!), but it broke the frames that did not contain transparency.
Now, those frames import with a black background. Before those frames used to import correctly with a transparent background.
Here's the differences between before and after the bug fix:

As you can see, the new behavior (top row) has the last three frames correct, but the others incorrect, while the old behavior (bottom row) has the opposite effect.
FS