I dont know what I've done differently from you guys. I have all current updates up to 10.6.2 (32bit) But this is what works for me:
USB
Keyboard & Mouse (trackpad) /both built in and usb
Sleep
Firewire
Bluetooth
Wifi with Airport (bought a supported card)
DVDs
Fully supported graphic acceleration
Time Machine
Gigabit Ethernet

What doesn't work so far:
Shutdown
Reboot

Haven't tested:
2nd Monitor
Docking Station

If you want me to upload any files or configs I have, let me know.

FYI: I can't update my signature/tag..on this forum, I think because I used "------>" in the beginning...

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Laptop: Dell D630 w/Docking Station
OS: SL 10.6.1
Ram: 4GB
GPU: Quadro 135m
Wifi: RTL8187SE
Audio: Sigmatel 9205
Not Working: Built in Ethernet (don't need it) and primary wifi card (not yet supported)