MSE message (maybe other adventures also happens)

Problem:

When I use Ranged Suport or WPP´s on the leader and kill the camp, this messages show up:

http://img836.imageshack.us/img836/6546/l1ej.png

I´ve used RS and WPP in many diferent adventures, but never killed 1 leader, only in this one I do.

i have had the same msg on other adv. no idea why this happens

Same experience when taking down a leader camp with WPPs.