Auto-complete leaks into 'from' and 'to' conditons, at least

Well, another one or two.

I tried to construct a smart folder to get all threads involving me as Sender or recipient. (It took some time to find out that 'keyword' is a fixed set. Anyway, better very flexible than too easy.)

Let me see, the steps:

1. New smart folder
   
2. Open some conditions
   
3. Type in some condition, see instant auto-complete, but in several conditions not this one alone (sometimes)
   At least general 'from' and 'to' accept, i.e. fill in the same auto-completes as another condition. Regardless of empty or filled already.

[[ Seems to work up and down the list. - but see next ticket ]]

Btw, I can't delete a smart folder which contains another one. The last crash happened after I created some nested folders and tried .
And I'm not sure what should happen to an edit window, when the folder it edited is deleted in-between. At the moment, it just stays.