Axiom Home Page Forums General Discussion Advice from Axiom Owners Onkyo AVR, HTPC and OSD

This is usually linked with a passthrough mode. That mode is either determined through some "source setup" option in the menus OR, it is automatic if the receiver only suports passthrough for 1080p. Since it probably does some processing for the 1080i/720p coming from your cable, there is fair chance you are in the presence of automatic passthrough/non-passthough.
You will have to look in your manual for the appropriate settings as all the Onkyo have a wide array of level of feature sets. Or your receiver does not support OSD over 1080p.