I'm going to assume that in addition to being a 1080p display, the TV can accept a 1080p input, right? Those two don't always go together, especially on early 1080p models. Unfortunately, neither my HD-A2 nor my HDTV support 1080p, so I'm not particularly versed in this issue. The HD-A20's manual (closest thing to your HD-A30, since that specific manual isn't listed on Toshiba's site yet) doesn't help much either. My suspicion is that the HD-A30 doesn't think that your TV will accept a 1080p input and is stepping down to 1080i because it is the closest input that the player thinks the TV will accept.