After updating to iOS 5.1 on 4S the display lights up with delay?

[onroad]

Hello,

After I updated my iPhone 4S to iOS 5.1 when I press the button it takes about 1-2 seconds for the display to light up for unlocking. Before updating the iOS it lighted immediately. I tried with restore but it didnt solve the problem. Can someone help me with this issue?

Thanks in advance!

 

[bab2010]

new iOS 5.1 bug maybe? i've never heard about this one.