Photoshop keeps playing up

[hits]

Photoshop keeps playing up. All of a sudden the shift keys stop working and the space bar doesnt work to move around canvas. I then have to restart for it to start working again. But then after a while the same problem occurs.

Please can anyone help? I would be most grateful.

Thanks in advance.

[dodginess]

What version of Photoshop are you using? What tools are you using in Photoshop?