just had to try the new update
all i did was download the file from apple, backed up my kernel, ran the installer, and before the reboot i replaced the new kernel with my old one from the backup.
i did not installed the old system.kext ( i did a backup anyway), and it seems i have no trouble using the 10.2 system.kext with qoops kernel (usb and everything works just fine - did not try the shutdown yet).

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CPU: AMD Athlon 64 X2 5000+
RAM: 2 x 1 Gb
2xSATA HDD
ATA DVDRW
MB Asus M2N Nvidia MCP61
Video: GeForce 8600 GT 256 Mb RAM
ADI 1988 onboard audio
Audigy soundcard
Realtek lan