I had a copy of the tpl_reviews_random.php file in both my default_template and my custom template sideboxes folder. I compared them with winmerge & then deleted the one in the custom folder (after making a backup of it) and now it's working fine.
Thanks for pointing me in the right direction.
If there's any issues with them, I'll know to check that backup copy to see if there's some info I'm missing.
Devlyn



