I, a druid, was in Servants of the Overlord the other day in a full party that included two other druids. Throughout the quest when I would cast Ice Storm a circular "Patch of Leaves" would appear on the ground and cancel my Ice Storm. The other two druids claimed they weren't doing it. Afterwards I logged onto my capped druid and went through possible combinations of spells but couldn't recreate the situation.
The graphic for the patch appears somewhat similar to the graphic under the vines when casting Entangle. When Entangle is cast over an Ice Storm the graphic is an Ice Storm with pulsing frozen vines and the ice storm isn't cancelled by Entangle so that combination isn't the problem.
There was a dryad running around that someone was summoning but during tests I couldn't get my dryad to do anything that seemed to cancel the Ice Storm.
Any guesses as to what this "Patch of Leaves" spell is? I would like to try to figure out more before bugging it.
TY