yes. REMOVE AAK!
android 2.2 and higher has app management built in. by having an app killer you are wasting more power and memory then you gain.
Android learns your usage habits and manages apps and memory accordingly. Apps that are "running" might not be using any memory and there for not using any power. force closing them will drain more power and if the app is something android/sense needs to be running and you force close it or the app killer closes it guess what? it will just restart using even more power.
The general consensus is if you have android 2.2 (froyo) and higher DON'T USE APP KILLERS! Just let Android manage your applications. after a few weeks you will see an improvement on battery life.