Following reports that PS3 isn't handling some backwards-compatible titles correctly, news that owners of 1080i television sets won't like. Some older HD sets only support 480i, 480p, and 1080i resolutions. The Xbox 360, when it encounters this issue, automatically upscales its 720p games to 1080i.
But PlayStation 3 downscales said games to 480p, says IGN:
This is the sort of thing you can't really find out about without a whole bunch of people getting their hands on a unit; it's unlikely that any writers with early access to PlayStation 3 units would be hooking them up to 1080i-only sets. Not impossible, of course, but unlikely. It's fair to assume that other little issues like this will spring up even more after launch day.
