Problems Adding to the Pre-defined Objects List

[Kittah]

I've encountered some problems with adding my own, new pre-defined objects to the list. I can add them to the list and click the save button on the right, the text-file is added to the folder and it stays there after I quit Graal.

However, when I return to editing a level later on Graal doesn't even register that they're there at all. Is it just me making a mistake with adding them, or is this a serious problem?