The kernel-2.6.21-1.3194.fc7 is hanging while booting on my Dell Optiplex 320. The last line is "PCI: MSI quirk detected. MSI deactivated". With kernel-2.6.20-1.2948.fc6.i686 and all other FC6 kernels, "pci=nomsi" is needed on the kernel command-line for it to see the SATA disk drive.
probably a dupe of 241249 can you try some of the workarounds mentioned there?
Adding clocksource=acpi_pm to the kernel command-line does cause the kernel to boot successfully.
That confirms that this is a dupe of 241249 then, closing as dup. Please reopen or file a new bug if the (to be released in the near future) errata kernel for bug 231249 doesn't work properly. *** This bug has been marked as a duplicate of 241249 ***