After long experiments, it works now!
I tested clean installation and update and hope that this works also on you.

Please try 0.6.0.1.
It's coming to maemo-devel.
Now available on maemo-devels.

I hope the new update don't remove this (anymore?).
To add the "All"-Category, try this:

1. Create a new category
2. Set "Category Name" to "ai_category_all"
3. Icon is (on default) "app_install_all" in "System-Theme-Directory"
4. "Save"

It should work.