ninja cleric bug

[oof]

So I'm fighting Shagbag and his gang at the end of Korgan's quest, and the cleric in their group lets loose with what I suppose is a spell trigger of some kind? The text I get is something like:

Cleric - magic resistance: cleric
Cleric - cloak of fear

Which would not be a problem, except that as soon as he casts this I become unable to select him as the target of any attacks, spells, ctrl+y's, etc. The red circle under his feet vanishes and it's like he becomes part of the scenery. Part of the scenery that's running around and casting harmful spells at me, that is. While I can still kill him by attacking in the split second before he gets the trigger off (and by area damage, I would imagine), I'd prefer to fix the bug rather than work around it.

So, any ideas on what could be causing this? I've got ToB, the patches for SoA and ToB, Dorner's ToB fixpack, gminions, and all of Gaider's stuff including the latest version of Ascension installed. Even a hint as to what type of file (.cre, .bcs, ???) might be causing this would be helpful...