Just to share a chance more....
For some reasons, my Darwin loader (from XxX 10.5.6 Universal) didn't return a smooth startup for some plist/bios issues.
(lately I discovered that was a bios issue of my old AMD Turion on a Pavilion HP DV8000 notebook).
Anyway, trying to fix this annoying startup issue, I totally erased Darwin using (not properly, maybe) OSX86tools and Fdisk/Install EFI functions. (Why this happened, I don't know....)
So I fell down on the tragic "boot0: mbr / boot0 : done" error
I tried using OSX86 again and again, testing all the possible choices (PC EFI, EFI+Chameleon, Darwin alone).
I even tried, as suggested on forums, to fdisk -u from the DVD terminal.
The only chance to boot my system has been, for two days, to use the DVD Bootloader.
My final and winning solution was to install the Netkas Zef Bootloader PC EFI v9 Chameleon v1.0.12 through this little app downloadable here (h-t-t-p://######.com/weaksauce12/?p=309), and launch it directly from Leopard.
Once rebooted, Darwin, incredibly, was there again.
Please notice that I tried it only once and on my "hack" machine.... so before doing anything I strongly suggest to CCC your OSX86 on another HD and then play and trick.