I had this problem and found that the rotation lock switch when in the on position also works to change the orintation when you press down. The slide across function only locks the switch from being operated. I belive a lot of people are resetting when all they have done is inadvertantly pressed the switch.
Our friend and comrade IronFly has reached his 10,000th post to our little Community. During the last 4 years he has helped countless Acer customers providing help, advice and answers. The Acer Community team feels honored to count you as our friend. Thanks IronFly!