Hm, did you try opening the ring description? I have Imoen pick it up by habit because she's removing the trap - and that seems to delay the dialog (at least it does in my game). When I put it to my PC's inventory that doesn't help either. But then I open the description of the ring and go back to gaming it fires as soon as I left inventory mode. -I play tutu though, so I'm not entirely sure about BGT.-