RHEL 6.2/Dell R710 UEFI install reboots to GRUB prompt

I recently installed RHEL 6.2 onto a brand-new Dell R710 with UEFI enabled.  It sees the 4TB drive array fine, and installs fine...but when it attempts to reboot after the install, it returns to a GRUB prompt every time.  I have tried booting to the grub.EFI file, which is installed in the expected place, but it returns me to GRUB each time.  Is there a problem with RHEL 6.2 and UEFI, or is there something I need to do specifically?  I have searched RHN from one end to another without result.