Posted in 10.6.6 thread too, but in case someone doesn't see this there:
D620, Intel 3945ABG Video, Intel WiFi, Broadcom Eth
I have 2 of these machines and I have installed Snow Leopard 5 different times on them.
My steps are as follows: Install from retail CD, boot from Chameleon, install bootloader,
reboot, backup /Extra, Replace with osxlatitude.com's latest EDP, run edptool, choose option 3, yes to appleps2, no to power and no to PCMCIA. Reboot, enable sleep via http://www.osxlatitude.com/groups/d4xosx/wiki/c1196/Getting_sleep_to_work_on_your_Dell_Latitude_with_OSX.html instructions. Run updates.
Each time I can get sleep working on 10.6.0 with no issues.
As soon as I install combo update 10.6.6 when I wake from sleep the mouse is horribly laggy and the rest of the computer just creeps along. Please help me!