Does it drop your data connection? I have experienced that since I installed it a week ago. Sometimes it will randomly choose to drop your data connection.
If its dropping your data connection, why haven't you uninstalled it already?
Seriously, there are things you can do with stock applications to improve your battery life, like turning off wifi, gps, data connection manually, all of which can be down easily with the Power Control widget.
Also, I noticed that there's a beta version of the app that is noted as being frequently unstable. Is this the version you're using? If so, buyer beware.