I have been doing a little research and feeling is using a task manager on Android 2.0+ is not the best way to handle Apps. It can cause instabilty of the App 'killed' or worse make the App fail to start when you next want to use it. I have found the following Apps and will explain what they do and my experience on my Scroll.
First I uninstalled Android Booster which I used to cease certain Apps via its Task manager just after start up.
I have now installed Start Up Manager v3.1. On opening the App you can select the User tab and uncheck the Apps you do not want to start up when you boot your Scroll. I have checked and the Apps no longer start unless I now choose to start them. The one thing I have noticed is better response when using the Scroll, it's faster.
I then installed an App called Watchdog. The purpose of this App is it watches running Apps and the amount of memory/ CPU the Apps are using. It will notify you if an App becomes aggressive by using to much memory/ CPU and you can then choose what to do in that event with that App. You can also have a desktop widget which can be configured for CPU in use/ running Apps.
Along with Battery Booster my Scroll is running very well.
Hope this works for you.
Thanks