no system disc (Intel i7 GA-EX58-UD5)

[XcsaS]

Non-system disk.....
Is what I keep getting and its driving me insane. For the life of me I can't get this installed. I am using iATKOS 5i OS X 10.5.5 my hardware specs are as follows:

Intel i7 Core 940
GA-EX58-UD5 Motherboard
9GB DDR3 1333mhz Corsair XMS
EVGA 260 216 core 896mb
WD 250GB HDD SATA
WD 1TB HDD SATA
Samsung DVD-Drive SATA

I have been following this guide for install:

http://www.insanelymac.com/forum/ind...=132960&st=620

When I install I put in the correct drivers (except the nvidia one which I have tried each one) I am able to install when it says it has completed and needs to reboot when it does it does not read the OS and I can't figure out why and its driving me nuts. Any help would be great thanks. Oh by the way I am partitioning the drive for 100GB and it is using MBR and the format is MAC extended not sure what I'm doing wrong.