After switching from Windows Phone 7.x series to Windows Phone 8, everything was great and perfect but something was unconsciously bugging me. Didn't take long to realize what it was: Pretty much every time I had to make the swiping unlock gesture twice in order to unlock the lockscreen. Why? Well, it's explained here.
Description of the problem
On any Windows Phone 8, after pressing the power button and immediately trying to unlock the screen, it won't respond to gestures.
This erratic behavior gives a bad user experience since forces the user to apply a second gesture to unlock.
This video shows in detail and compares a Lumia 800 (WP7.5) vs Lumia 920 (WP8):
Hope you will be able to reproduce the issue and fix it soon.
[As posted on Windows Phone feedback page]
Customer support service by UserEcho