I have Sony Vaio VPCCA laptop, which have hybrid graphic cards Intel and ATI. I had tried the catalyst drivers from AMD to switch the cards, but with no luck.

New release of the driver version 12.1 is available and seems that it had/has fixed the issues with switchable modes. I can confirm that, i have installed the drivers and every thing just works.

Had replied to a thread in openSUSE forums with the installation procedure in detail, here is the specific post from the thread. Hope it will work for you.