I have installed to versions of Ubuntu, one up-to-date Xubuntu and a 12.04.5LTS Ubuntu. I first installed Xubuntu and later Ubuntu. Since the 12.04 would not write a correct grub-conf on install (I set up encryption for Xubuntu following this guide) i decided to let the grub conf on the efi partition load the grub conf from Xubuntus /boot partition. While I can now boot both OS's I get some errors about grub not being allowed to load some modules (error: Secure Boot forbids loading module from (XX,YY)).
I assume that this has something to do with efi and beeing signed. What is the easiest way to fix this? Can I simply reinstall grub from the Xubuntu?