susceptible to fire?

[onomastikon]

Why for some reason do many of my troops in a battle become "susceptible to fire"? I cast protection on them, but nothing else I think...?

[Wauthan]

Too much beans and cabbage in their rations? Sounds like a bug to me.

[Gandalf Parker]

Certain things have chain events. Such as I had my carrion dragon casts a fire aura spell and I noticed that it did that AND made him susceptable to fire. OK I guess that makes sense. If Im going to fire-aura him I better do a fire protection first.

[Treebeard]

So a bark-like skin means susceptibility to fire. Makes sense, I think.