Angry [q] back button and menu not working

Dear all,

I donīt know if this is a correct forum for me question, but I have a small problem. Any days ago I have broke me screen of Optimus L9 P760, I buy the screen and remplace the screen, at the moment all working perfecte, today I opened the new the mobile for clean the LCD, when I repaired I touch the lcd and appears my fingers.. ;-P. When I return to close the mobile and restart the mobile, the back button and menu not working but the screen touch working perfect.

Please, could your help to me?

And sorry for me bad english.
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Phone: Samsung Galaxy Ace
Baseband: XXKPP
Rom Modificate: CM10.1 - SGSIII - RC1 - Plegimus
Base Rom : CM10.1 - NIGHTLY - bieltv.3
Kernel: Erickas and Wayland_ACE
Script: nothing
Recovery : Clock Recovery 5.0

Phone: Samsung Galaxy S
Baseband: XXJVT
Rom Modificate: CM10.2 - SGSIII - Plegimus
Base Rom : CM10.2 - NIGHTLY
Kernel: SEMAPHORE
Script: nothing
Recovery : Clock Recovery 6.0