iPhone Slow to Wake/Screen Problem

My iPhone has been like this for two months (see link for video). Its extremely slow to wake (this video shows it waking faster than it usually does) and it has a powerpoint-esque windowshade animation looking animation when it wakes (visible in video). The longer the phone has been on and used for, the slower it is to wake. Any ideas on what I can do to fix this? I've already tried doing a software reset, but that didn't fix it. Its not jail broken and it is running the latest version of iOS. Its a CDMA White iPhone 4 16gb.

http://www.youtube.com/watch?v=41O52VRUvAc&feature=youtu.be

blueroom said:

Could be a rouge app.

Do a DFU restore and put the apps back one at a time.

Click to expand...

Just did two back to back DFU restores and set it up as a new iPhone. Problem is still there.