I have a 10.6 system following this guide. I never used sleep enabler though.

Some people might be interested in the way I test updates now. I use carbon copy to clone my current drive (i was made following this guide). Just reinstall chameleon bootloader ( here ). That will give you a perfect copy of your system that is bootable. boot into the new system from bios. try your upgrade configuration. If and when it doesnt work. go to carbon copier again clone your working drive again, this time it wont take very long to clone your drive since it compares files before it moves them. it is awsome.

I am trying to update this system too and I am having trouble. I have gotten 10.6.2 to work.

Update
add new sleepenabler (i didnt have old one)
delete extentions.mkext
rebuild as advise earlier in thread.

got it to boot buuuuuuut

its weird. it doesnt sleep like my current system does. ethernet issues. etc...

i'll keep a look out and I can try a few tweak everyday till i get it. with this carbon copy work flow it is easy to test out changes. good luck. look forward to other results.