Jason and others,
We have an OpenACS install running 5-1-5 with file-storage package version 5.1.5d3. Files are stored in the filesystem not in DB. File versioning works fine for us just changing original file in /package/file-storage/www/view/index.vuh with the same file from HEAD.
Could you please try if it will work for you? Just download index.vuh from here
http://cvs.openacs.org/cvs/*checkout*/openacs-4/packages/file-storage/www/view/index.vuh?rev=1.2
and copy this file as your file-storage/www/view/index.vuh working file.
Please, let me know if it worked for you. Thank you.