Inconsistent problem with burn folder behavior.

I frequently create Burn folders to create archive discs for myself and my client so I have backups in two locations. Typically, I create a new Burn folder and begin dragging project folders into it. Sometimes I get the expected alias of that folder and I can inspect that folder and see all the contents of the original folder there.

But more often than not I get a 5.8MB document (always it's a 5.8MB) instead of the alias. Click on that file and I get a window that says "There is no application to open the document <folder name>." This document is usless as a back-up. What's going on here?