I'm getting the "HFS+ Partition Error" message that is theoretically covered in the FAQ under: "I have booted OSX many times before. "
I've read most of the standard advice on this and tried it: reset the active partition from the Ubuntu Live CD, run Disk Repair, run Fdisk from OSX Terminal, etc. The only thing I haven't attempted is installation of the Acronis Boot Manager.
I believe what may have happened is that the hard disk lost the Darwin Bootloader in the boot sector while I was experimenting with NP's various builds of the NVidia Beta driver.
Previously, the system was dual-booting successfully between Windows XP and 10.4.3 through the BootIT NT boot manager (this is similar to Acronis and available at
http://www.bootitng.com/).
After one "black screen" experiment with the beta NVIDIA drivers, I had to restore the BootIT NG boot manager, and from that point on, any attempt to boot the OS X partition produces the error: "HFS+ Partition Error."
I can still boot successfully into 10.4.3 by starting from the Installation DVD, provided that the HFS+ partition is marked active on the hard drive. (I know the HFS+ partition can be set active in a number of different ways.) But the "HFS+ Partition Error" appears in any attempt to boot from the hard disk, itself, including attempts to use the C:\Chain0 method from the Windows XP boot loader.
The HFS+ partition is the second primary partition on the drive, the Windows NTFS partition is the first primary partition. When installed, BootIT NG is a third primary partition. One of the features of BootIT NG permits it to rearrange the partition order seen by the boot loader in any order that you like. This worked perfectly before the system crashed. (It's also useful for avoiding the red "cannot boot from this volume" message in the Installer program. BootIt NG allows the HFS+ partition to be seen as the first partition on the disk, no matter where it's physically positioned, which tricks the Mac Installer into giving it a green arrow, at install time.)
I've additionally experimented with removing BootIT NG, entirely, restoring the NTFS boot loader from the Windows Recovery Console, and attempting to boot through the C:\Chain0 method. All these attempts produce the "HFS+ Partition Error" startup message, although the system boots flawlessly into the HFS+ partition from the Installation CD. (And the newest NP drivers now work fine with the NVidia video card.)
I've concluded that the Darwin Bootloader must have somehow been erased from the hard drive, and am uncertain about how to put it back. I experimented with using dd to capture the first 512 bytes of the CD and transfering it to the hard disk, but that didn't work. There are also some reference threads about copying the /usr/standalone/i386/boot file to a floppy disk, booting into single user mode and using a utility called Startupfiletool to copy the boot file back to the hard disk. (See
http://forum.osx86pr...php/t2839.html)
Unfortunately, neither the OSX installation disk or OS X in single-user mode seem to support mounting a USB floppy drive, so I haven't been able to try that.
I'm wondering if anyone knows precise syntax that can be used with the dd command (without using the startupfiletool utility) that might be able to restore the Darwin boot loader without overwriting the partition information in the boot sector.
I also have a hunch that simply running an "Upgrade OS" installation from the DVD would refresh the Darwin bootloader and allow the system to boot from the hard disk, again. But after all the tweaking I've done, I'm reluctant to risk starting all over again.