Sorry for the late reply - You are indeed correct regarding this issue. None of the backalign settings were working, except the default "TL".
This bug crept into the system from the last update when I added a "solid color" tweak to create a virtual 'background color' even when running the gallery in SWF mode.
I have fixed the bug now -You can check with the example links on our backalign documentation page:
https://www.photo.gallery/469
The new updated "imagevue.swf" file is updated and available in our downloads section, also as an individual download:
www.photo.gallery/downloads/
Thanks a lot for your help and patience in this matter!