Post install snow leopard

I've used Tonymac's iboot and multibeast to install a retail copy of OS X, below is my system information:

<<< System Summary >>>
> Mainboard : Asus P5G41T-M LX2/GB
> Chipset : Intel G41
> Processor : Intel Pentium @ 3200MHz
> Physical Memory : 8192MB (4 x 2048 DDR3-SDRAM )
> Video Card : NVIDIA GeForce 8400GS
> Hard Disk : Hitachi HDS721010CLA332 ATA Device (1000GB)
> Hard Disk : BUFFALO HD-PCU2 (320GB)
> DVD-Rom Drive : Toshiba-Samsung CDDVDW SH-S223C
> Monitor Type : Dell Computer DELL SE198WFP - 19 inches
> Network Card : Realtek Semiconductor RTL8168/8111 PCIe Gigabit Ethernet Adapter
> Operating System : Windows 7 Ultimate Professional Media Center 6.01.7600 (32-bit)
> DirectX : Version 11.00

The problem i have is that when I install os x, and chrimeria, it boots at 1024 x 768, I have no other options to display. as i understand it I need to edit the geforce driver with System, Library, extensions, the NVDAN kext, however when I get access to the plist, I can't edit it. Also, installing the Enabler or the driver package doesn't work for me.

Additionally, the safari and Firefox crash on Youtube, the only browser that works effectively is Opera. As for sound only voodoo kext works. Installing the kext for ALC887 does not work, so the volume can never be adjusted properly, and under voodoo the volume has to be adjusted through the speakers.

Also shut down on occasion fails to work.