Graphics
For your 9800GX check this link out http://forum.insanelymac.com/index.php?showtopic=98666
Remove any other kexts related to video and make sure to to properly set permissions.

Seatbelt
Give this seatbelt.kext a try. It should be pre 10.5.6 http://rapidshare.com/files/178549460/seatbelt.kext.zip

Installation
You can use kexthelper or refer to this post where manual installation has been described. http://www.infinitemac.com/f5/kernel...nt-file-t1834/

Let us know if it worked out for you. Also place your system specs in your signature. That will help us out.

---

MOBO: Z77MX-QUO-AOS CPU: Core i7 3770K GPU: MSI N760 TF 2GD5/OC Case: Modded MacPro2,1
Memory: 32GB Corsair Vengeance (CMY32GX3M4A1600C9) Wifi: Airport Extreme bcm94321MCA BIOS: HermitCrab Labs H3A.816M
Monitor: AOC Q2963Pm 29" WFHD 2560x1080 21:9
Interests: KDE on Apple Darwin, Keeping it real with the command line, Helping those that help themselves