Thanks to all the great info on these fora (and occasionally elsewhere), I have successfully installed Mac OS X 10.5.6 (well, starting with 10.5.4 then updating) on my Mini using the DellEFI method (thanks, mechdrew!). Everything went about as smoothly as possible, and I ended up with a system that booted cleanly into MacOS. Wow! color me amazed!
Not satisfied, I attempted a Win7 beta install. I knew this was a bit risky, but given the 64 GB disk on my mini, I just had to. Also, since Win7 supports GPT disks, I thought it should be relatively straightforward. Well, that process had a few more stumbles, but I did successfully get Win7 installed, and the machine now cleanly boots into Win7.
And that's essentially the problem. Both installs work great, but in order to boot to the Mac partition, I have to boot off a USB stick with COM32/Chameleon on it (the one involved in the initial booting of the MacOS install in the DellEFI process), which means turning on USB legacy compatibility, which means no sleep in MacOS. Also, I thought that this bootloader was generic enough that it would load any OS, but when I do boot that way, and select 81 for the "second" HD, it only shows hd(1,2) as an option -- doesn't seem to show the Windows partition.
I tried re-running DellEFI from within MacOS and telling it to re-do the PCEFIV9 bootloader, but that didn't change the behavior. I also tried a Chameleon install on its own, but it still boots Windows.
Can anyone point me in the right direction for learning more about setting up multi-boot in an emulated EFI environment with a GPT disk?
Thanks in advance!