I've found numerous reports online of people experiencing this. I've tried it with GDMenuCardManager v1.33 and v1.35. I've tried it with a VGA connection and a composite connection. I have an NTSC-U console with a Bitfunx GDEmu v5.15b (clone). The regular GDMenu works fine, but OpenMenu just gives a black screen with the VMUs showing the OpenMenu logo. The proposed solution of removing the VMUs does nothing. Has anyone found a way to solve this?