xpress 200 with component-out fglrx in 720p

I have an xpress 200 integrated video board with component-out cable. It works great in text mode, it's sharp, no flicker. I'm using the fglrx drivers in X windows, but strangely with component-out I can only get it to display properly in 1080i. It's 30hz so it's a bit flickery, and the tv is native 720p so it's downscalled and looks fuzzy. When I set the resolution to other non-hdtv modes like 1280x1024, it appears to display in 1080i with black bars. When I set it to another hdtv mode like 1280x720 60hz, the display is completetly screwed up, almost like the tv is trying to display a 720p signal in 1080i or something like that. Does anyone know the trick to get fglrx to display 720p over component-out properly?

Sorry, I'm a moron. Turns out the TV is not native 720p. It's got 800 somthing scanlines and only accepts 408p, 480i, and 1080i on component input. It's a 5 year old Samsung TXM-3098WHF. The motherboard is a DFI Infinity RS482.

I was just using the default X11 config after installing ubuntu and the fglrx package. It was working in 1080i mode with no special configuration.

I think the relavent lines are:

(**) fglrx(0): *Mode "1920x1080": 74.2 MHz (scaled from 0.0 MHz), 33.7 kHz, 30.0 Hz (I)
(II) fglrx(0): Modeline "1920x1080" 74.17 1920 1963 2004 2200 1080 1084 1094 1125 interlace
(**) fglrx(0): *Mode "1280x720": 74.2 MHz (scaled from 0.0 MHz), 45.0 kHz, 60.0 Hz
(II) fglrx(0): Modeline "1280x720" 74.17 1280 1347 1384 1650 720 725 730 750