There was a bug in F19 that had a similar error on Macs, but it was fixed in time for F20.
Seeing as how you're most likely not using a Mac, how are you mounting the UEFI partition? Is it sharing the Windows UEFI partition? One thing I've done in the past is creating an additional EFI partition. I believe they fixed the issue with sharing it with Windows, but if it's not working on your hardware, I would create another one and just give that to Fedora. The only drawback that I know of is that you won't be able to dual-boot in GRUB, you'll have to load up your UEFI utility and select which OS to boot.