Hi. I started having a weird issue with my MacBook Pro, 15-inch, Late 2011, OS X 10.9. If I press for example left command + left shift/control/option + a, the mac only receives command + a. If I use the right shift/option it receives the correct input. Also if I use the right command + left shift/control/option it works fine. All keys work independently fine and there's an issue only with the left keys combination as I described. This makes me think there's no hardware issue. I tried: - restarting mac - creating new user profile - cmd + option + p + r reset - disabled all keyboard shortcuts from System Preferences -> Keyboard -> Shortcuts - Dictation and Speech are not enabled All failed. Any ideas? Thanks.