Weird bitmap scaling in Captivate 9?

I've got some projects originally started in Captivate 7 that are publishing weird in Captivate 9.

Some, but not all, of the bitmaps on the stage are blurry when published. It's as if they're being scaled to a slightly larger size, even when they're on the stage in their original size. They look the way they should on the stage, it's just when previewing the project or when published that they're blurry.

I found that if I resize the image down slightly on the stage it looks correct when published—for example, an 800x560 bitmap, when on the stage at original size, looks blurry when published, but if I change it to 799x559, it looks fine.

Images look fine in HTML5, so it's only a problem in flash output.

I have tried removing the image from the stage, and the library entirely, and re-importing it and placing it again. Still blurry. I have also tried creating a new presentation, copying and pasting all of the slides over to the new presentation, and that DOES seem to fix the problem. Of course, that would be a major pain in the ass  to fix for multiple projects and would be a last resort.

Any thoughts on any resolution to this that doesn't involve recreating everything?