I have the same problem and i had write a complaint in this forum before, now my iphone 4s is back to normal with the latest ios 5.0.1.
my problems start when i click on software update that pop up in general setting. after update then the problems start..
last night i try my luck with restore my phone to original setting. I plug in the phone and connect to itunes, i click on restore. Then itunes start downloading the latest ios 5.0.1 to restore to my phone.
Magically.. after restore...all things is back to normal...and my battery last longer..
I just dont restore from backup..
all my contact i get back from icloud.
At least im trying something before i decide to change my phone..
and its work!
Iphone 4S IOS 5.0.1 no problem at all...