F16>F17: F17 can't find root by uuid - which exists!

[sean darcy]

Upgrading from F16 to F17. F17 boot fails because dracut can't find the 
root partition, which is listed by uuid. This is the same uuid used in 
F16, and when I run blkid at the dracut prompt : there it is!

And yes, I've checked character by character.

I changed fstab to use /dev/sda2, but that doesn't help. How do I edit 
grub2 to point to /dev/sda2 so at least I can boot?

And anyone know why dracut is having such a problem with uuid?

sean