So your 990 is connected to the TV via S-video or composite to input 4 on the TV, and your DVD player is connected directly to the TV via component to input 5?

If so...

Why not just connect your DVD player to one of the component inputs on the 990 and then connect the component out on the 990 to input 5 on the TV?

This is how I have my DVD player connected, and I get OSD and the DVD video on the same input.