[Naiya]

yup - 100% repro.

If the creature had no path to me (happened most often on hills - as you noticed as well) we were fine the the stupid thing would just heal. When I soloed on Lillibell this weekend, The mobs would just heal insanely (as you noticed) I was going to bug it but was advised it was "as intended" to prevent perching with pathing issues were discovered. I used the same workaround you did and was fine for hours.

Didn't notice any problems until Taggy and I teamed. If Taggy pulled (he is the tank of our duo) and the creature had no path we would get a few attacks in and *bam* dead chunk

Another interesting thing to note (not sure if it is related or not) when we logged back in *I* would have the three minute invulnerability buff.... Taggy would not. He would be attacked right away

We were in shoreline ruins with Niaya and McTaggard (the URT weapon mission... which is borked for us and I'm just to frustrated to go back and redo the damn thing) and in the Orc starting area with Groknor and Eyeof. I can't remember the quest name but it was the one where you went in the caves to kill kliknacs and the wyvern looking things so you could join the clan