error deleting item

[bmos]

Script Error: [string "campaign/scripts/masterindex_window.lua"]:578: attempt to index field '?' (a nil value)

to reproduce (pathfinder/3.5e):
1. empty new campaign
2. new story entry
3. enter name for story entry
4. in stories window, delete story

i think the story title is delayed in writing until focus on field is lost, but it isn't lost when i go back to the stories list and delete it