Documents in BPS Web Interface

Hello-

Pardon my ignorance, but I'm new to using the web interface builder for BPS.

In Cost Center Planning, the desire is to store one set of comments per Cost Center. The Layouts are by Cost Center, Cost Element, Year and Version.

I can't seem to figure out the settings. I have COst Center, Version and Year ticked as Document Attributes in the Cube. No matter if I select Row or Cell in the Layout settings, the comments aren't saved. I can enter them, but when I come back in they are gone.

What am I missing?

Thanks!