Suddenly, as it had worked before many times, selecting Scalable HTML Content doesn't work. It actually shrinks the content to a postage stamp size. This happens only in SWF output. Whether that's done using both HTML5 and SWF or SWF alone. The same error occurs.
I created a small test file and it worked fine - the project I've been working on is the on failing.
Any help tracking this down is appreciated and needed.