How to enable my Ati Radeon HD 4670 with iatkos S3

I kindly request help on following problem.

I have a new desktop PC which I use as a multi boot machine. I have a W7, two XPs and two Linux distros smoothly working in one. I am now trying to add iAtkos s3.
My motherboard is P5K and the bios is crossflashed with P5KR bios in order to enable the ACHI mode under SATA options. I have 2 HDDs and they are partitioned by MBR method not GPT. I create the SL install partition with iAtkos install DVD.
My CPU is Intel Core2Duo E 7800, 2.9 Ghz. and graphic card is Ati Radeon (HIS branded) HD 4670, 512 MB with dual DVI. I have no VGA plug.
During installation I choose default options. I choose PC-EFI, graphic enabler and Chameleon RC5. The
Installation went normally. After restart, now I can here a nice music but no graphic response. (Total blank screen) As I guess, the problem is graphic card kext.

I am not experienced on Mac OSX, unfortunately. I read a lot on Insanelymac, Netkas, Tonymacx86 and Osx86 forums during last 15 days. It just makes me more confusing. It is so hard to find exact driver and information among millions of topics and details.

Can you and describe simply, how can I make my graphic card work normally.

Any help is highly appreciated. Thanks.