Power Button software problem

[PowerButtonprob]

My problem when i hold the power button longer then no window comes and i cant make a screenshot because it dont work with the button. To lock the phone works, but the other thinks not. It must be a software problem.

I have the Xperia SP with the Android version 4.3 Jelly Bean. Its not rooted or something like this.

I hope you can help me or somebody can report this. I mean it can be right that i cant shutdown my mobile phone or make a screenshot!

Thanks for reading and sorry for my bad english, I'm from Germany

[sazzz]

I'm having the exact same problem now but my screens froze and I can't turn my phone off! did you fix the button?

[ahypernova]

Tank for this tip. I have same problem

[zagna2]

Same problem here. I cannot bring up the power off menu by pressing long the lock button... I must push the off button in the back of the phone so i can restart it. What a fail phone is it really?... What else i will see from this phone.... Jesus Christ!