This occurred on a freshly-downloaded 64-bit iso, alternate install.
It also occurred on a hardy install, alternate, 64-bit. In this case (since I pursued the install to viability), I can verify that the grub package was _not_installed.
Perhaps my hardware is just too unusual...
Motherboard: Biostar TA790GX A2+
CPU: AMD Phenom 8450
BIOS: AMI v02.61
Motherboard chipset: AMD790GX
4 GB of memory
Disk is a 5-disk SCSI hardware RAID on a Mylex eXtremeRAID 2000 controller (module DAC960)
I have been using the Mylex controllers for several years, with no issues until very recently, in attempting this new build.
Please let me know if there is any other information I can supply.