Automatically & constantly Switching between playback/camera mode

My A610 Canon Camera suddenly started this strange behavior!
It automatically switches between playback and camera very quickly but only for a while, then either it works fine for some shots or it remains in playback mode.

I gave it to a Canon authorized service center and after one week, they called back and told me the problem was cause by the playback/camera switch which just needed a cleaning. I checked the camera which was fine even after some turning on/off.
BUT when I arrived home, the problem started again!