Let's try this over:
Make your USB stick, but don't use myHack! DO NOT ON SNOW LEOPARD... Last thing you want to do. Here's what you want to do:
Insert your Snow Leopard install DVD or if you have a DMG image that works too. Go to disk utility and format a USB stick with Master Boot Record and Mac OS Extended (Journaled).
Go to the Restore tab, and for source, click "Image" and select your Snow Leopard DMG file or from the DVD menu if you have the DVD version. For destination, drag your formatted USB drive to the destination section. If you are making it on Snow Leopard, be sure "Erase Destination" is selected. On Lion and Mountain Lion it does it by itself. and then click restore. Enter root password and let it copy away!
Now download the latest certified Chameleon bootloader from here: http://www.osxlatitude.com/files/Chameleon.pkg
Download this bootpack and put it on the root of your USB stick: http://www.osxlatitude.com/packs/Dell/Dell_Latitude_D4x0-sl.zip
Now boot from your USB stick using "-v" or "-v -f -x" and then install OS X. Make sure the hard drive is formatted Mac OS Extended (Journaled) and GUID Partition Table. Now install and when it's done, update to 10.6.8 and run EDP 1.9.2 and make a build. Now reboot. If you want you can also install myHack Utilties and run myFix Full mode
Cheers!