Cuberevo HD Twin Tuner Component Video HD?

I recently got one of these, not all hooked up yet but because I can't get HD through to my TV (the TVs fault) I am reliant on using the Component Video output to try and get 1080i. The spec for Cuberevo and my TV (JVC LCD26-DX7) both say this is possible (i.e. the Cuberevo should output at this through Component and my TV should receive at this also). However, when I boot up I can only get SD-Pal and in the AV Setting I only have options for RGB or CVBS (Composite Video) under the AV part and resolution selection of SD-Pal, 720p or 1080i. I know that I can interrupt the boot and get other options, including 1080i/50 or 1080i/60 (best for my TV I believe) and I've tried this, but when I amend settings trying to get the component video output to work I get nothing (at least the screen on the TV changes from blue to black so its almost working). I know the component input on my TV works, I have used it for DVD. I am using Image NLB 8833. Do I need to change my Image - I have heard some folk refer to a YUV settings choice for component output (?), if this is anything to do with it I can't see this option. Remember, I'm, not all hooked up to sats yet (installer coming on Sunday), is this why the component output appears black or should I be able to see boot and set up screens through component video and not just scart. There's somthing not right and I really need this to work. Thanks.