easy solution.
1. use sbsettings to restart into SAFE mode (sbsettings->power->safe mode)
2. unlock phone, start up an app or two
3. exit safe mode (respring)
that's it. no need to delete any apps or anything.
this happens to me every time i reboot my iphone, i just follow these steps and it's solved. i have never not had this occur on my phone, even after a fresh install. not sure what's causing it, but this is the solution.