What's the difference between dell EFI 1.2a5 and the current pcEFI ?

There is a bootdisk image I used to rescue my netbook a few times over the last year when I goofed up, during upgrades that allowed me to boot my netbook with a CCC'ed image of my snowleopard install from a usb HD, the catch is that it doesn't work with versions greater than 10.6.1. I would like to see this this functionality in later versions of pcefi, but I really dun know where to start fixing this. The problem is I can't really track down if it's the Dell EFI or something in the chameleon that has changed. would be great if anybody with a hack, be able to rescue their mac's by just sticking in a usb HD and letting an osx image boot from USB.

Here's the link to the boot-disk [url]http://www.mydellmini.com/forum/general-mac-os-x-discussion/6979-working-usb-boot-disk-chameleon.html/url] I've tried to install that same version of chameleon onto a usb HD and had no success whatsoever to let it boot directly. So I think it's something that has to do with that dellEFI thing.
Anyone here have a clue on how I can get this t6o work with later versions of snow? Cause in order to boot later versions of snow I need higher versions of chameleon but they have the pcefi integrated in the boot file. So is there anyway to add usb booting capacity to current versions of pcEFI? that would be great to rescue all my hacks.

terramir