Hi Stese,
Getting there!
I did the BIOS update, then booted off Fedora Core 5 disc 1, and this time there was good output re: PCI bus. Installer started up fine. But I'd downloaded Fedora Core 6 last night, so decided to try that. Booted off THAT install disc, and it hung at the same place as you wrote above -- agpgart etc.
I tried tweaking BIOS settings, no luck. I also tried various kernel arguments (pci=noacpi, acpi=off) but no change. I have very little idea what those even mean anyway, but ahead of the agpgart hang, there was an acpi "AE_NOT_FOUND" error, so I thought that might be related...
Anyway, more googling took me to a forum thread here: http://forums.fedoraforum.org/forum/showthread.php?p=680436 which is about FC 3, but still a similar problem...someone's reply said "pass this before proceeding with install: linux agp=off" and that worked for me! It started right up and the installer ran happily in graphical mode, mouse worked, everything.
It's installing now...crossing fingers. Will post here with result.
...
Edit: Seems fine as long as I retain the "agp=off" option at the end of the kernel line in grub.conf. Otherwise it hangs at "OK, booting the kernel."
Thanks folks!