ATI recognition issue

Hi all!
I’m using OpenSuse on all my home computers (yes even kids’ desktop is opensuse!). I’ve just bought a brand new acer laptop (aspire 7535G) and of course installed OS 11.2 on it. So far I have no real problem, but one thing bother me:
The laptop has an ATI RadeonHd 4570 witch is a kind of dual GPU because it also feature the RadeonHD 3200 when unplugged. (at least it’s the case under windows vista) and you can switch from one gpu to the other througt the Catalyst App.
The prob is whatever I did, the only GPU that is recognized under OS 11.2 is the radeon 3200! I’ve installed the catalyst driver 9.11, everything works flawlessly, even Kwin effects, but I’ve a very low fps under glxgears, and the amdcccle app tells me I only Have 256 MB VRAM and I have 512!
Is there a way or a trick to activate the 4570 GPU?