Endless reboots after Tiger/Leo install in ACHI on P5K-E/Wifi

[StopMo]

I had previously successfully installed 10.5.0 on my P5K-E Wifi/AP (BrazilMac, prepatched), but could only boot from the DVD, and wasn't able to get back into my windows partition or get multi-booting to work using any of the scripts or terminal commands I've found on this site and other sites.  Most install guides recommend first installing Tiger, then installing Leopard.  I actually want to tri-boot, with Leopard, Tiger, and Win XP.

 

I got tired of not being able to get back into my windows install, so I reinstal

ed Windows, repartitioned my drive using Gparted LiveCD, creating 4 partitions - 1 for XP, 1 for Leopard, and 1 for Tiger, with about 75 GB left over on the 250

B drive left unallocated. (I had used Acronis out of XP before), and then installed Tiger on two different partitions (JaS 10.4.8 using semthex's kernel, *not* installing other languages, etc.).  I could get Tiger to boot okay, but still only using DVD.  If I took out the DVD, I would get an error message (something about the plist, showing the directory where the error was - /Apple/preferences/**plist, or something like that).  I installed it also to my Leo partition, so I could hopefully get rid of the boot issues I had not installing Tiger before Leo in my previous install attempt.

 

I proceeded to install Leopard over Tiger successfully (had to actually re-install Tiger once since I had left the install unattended and the extra languages were installed, making it impossible to uncheck those additional language options when it was time to install Leo, which led to an error about not finding the necessary files on the install DVD).  Got the reboot message, and clicked "restart".  Upon rebooting/resetting, though, the machine got caught in an infinite cycle of reboots.  It would start reloading the Leopard installation/Darwin bootloader if I left the DVD in, and it wouldn't boot into Windows at all without a dvd in the drive.  It would just keep rebooting over and over.

 

I went back into my BIOS and changed the SATA settings back to IDE from AHCI, and I could almost boot back into Windows.  Changed it back to AHCI again - bang, reboot cycle again.  I finally booted with Acronis rescue disk and was able to reset my Win partition as the boot partition (which I think I actually did before I could get it out of the reboot cycle) - this, coupled with leaving the SATA setting to IDE, let me get back into Windows.  I could see my Tiger and Leopard partitions, but of course couldn't access the data from Win XP.

 

All this is especially puzzling given that I was able to get Leo running before without Tiger (after I had installed Windows XP Pro SP2), even though I had to boot with the DVD.  My XP partition was still intact, but I wasn't able to re-activateit  in Acronis because it wouldn't recognize my USB mouse in Safe Mode, and full mode would give me "Acronis is unable to find any installed hard drives" (why Full Mode gave this error when safe mode didn't, I have no idea).  I simply couldn't perform the Acronis functions completely without a mouse.

 

So, with both the Tiger and Leo installs and DVD's, using AHCI kicks me into a vicious reboot cycle, which only reactivating my C:/Windows partition and setting SATA back to IDE seems to fix.

 

Any ideas?  Hardware failure on the part of the AHCI controller on the P5K-E MOBO?  Why could I get Leopard to boot from the DVD in AHCI mode before, but now, post-Leo-on-Tiger, I'm getting this constant reboot problem?