...where, precisely, are you putting this new state of dialogue? It would belong in the P DLG
I put it in the pre-joining file, not the xxxxj.dlg or the xxxxp.dlg. I followed Bioware's example where they had put Keldorn's "hello, how are you stuff" in his Keldorn.dlg (or Keldor.dlg I forget which) if you didn't pick him up for the Eyeless quest and wanted him to join the party when he was in the Radient Heart.
My triggers are being met in the the script because I have DisplayStringWait checks to see what is happening. I wonder if I can force it to stop doing the kickout/rejoin with a SetGlobal("NPCJoined","LOCALS",1) in the script prior to the Dialog(Player1) action. Inelegant, but it may work.