would a normal computer monitor display 480i?? I don't think the front-end menu supports anything but NTSC output (or PAL if you're in a PAL region). I know there's a key sequence for booting the PS2 into NTSC mode when using the Linux kit, but I've never used it.
The linux kit is neat, but I haven't been able to mess with it at all for over a month because I can't have my PS2 networked to the PC right now and I refuse to try and do anything with it on the TV. Before I had that happen I had compiled some VU demos which were pretty neat and had setup FTP, and a VNCserver so I could log into it via my PC. It's a neat piece of kit, and hopefully since I'm interning next semester and won't have much classwork to do I'll be able to play around with it and actually get to coding some vector units (which is my main interest over programming the MIPS core, but hey, maybe I'll do a bit of both).