Problem with double click mouse to open

Hello, I have a little problem with the mouse in Cubase Elements 7. Specifically when I double clik the mouse.
I don’t know what happens but suddenly not working the double click of the mouse, for example to open the midi editor or open the inserts plugins. Finally I’ve got to make it manually, going to Midi menu at top of the cubase interface…
I’m very confused with this so could you give me a hand, please?

Thanks

You need to find the right pixel to click on

I don’t know exactly what you want to say with the “right pixel”, in any case, I allways use double click anywhere in the colored midi track.
So far when you double click in the midi track allways opened the midi editor
:confused: