HDTV flicker

[Andy Mac]

I will be getting a new TV when I get back from Kazakhstan, however my current 51" rear projector seems a bit 'flickery' when panning quickly. It's doing my nut in. It's a 1080i, as it's a little old, and my new one will be 1080p, but I'd like to know what is causing the flicker, as this TV will be for arsing around on games, etc, down in my sisters basement. Any ideas? It's connected with HDMI, and Blu-ray player is a PS3.